This 15-minute Cold Tuna and Tomato Somen is the noodle you need for summertime! With savory tuna, juicy tomatoes, and chilled umami-rich broth, you’ll be happily slurping away even on a hot day. Best of all, it’s a breeze to make.

A glass plate containing Cold Tuna Tomato Somen topped with julienned shiso leaves.

Summer in Japan can be brutal. The heat, humidity, and sweat. It’s too easy to lose an appetite on those hot days, but you have to eat and keep your energy up. The remedy? Japanese cold noodles.

Today I’m sharing Cold Tuna and Tomato Somen (ツナとトマトの冷やしそうめん), which takes just 15 minutes to prepare. Give it a try, and you’d know why slurping super cold noodles is a must in Japanese summer.

Japanese Cold Noodles

First, let me introduce a few other cold noodles that are popular in Japan. We basically live off in a variation of these cold noodles all summer long. They are light, refreshing, and yet deliciously flavorful.

A glass plate containing Hiyashi Chuka (Cold Ramen).

What Are Somen Noodles?

A blue glass bowl containing somen noodles.

Sōmen (素麺,そうめん) are white Japanese noodles made of wheat flour and they are threadlike thin, about 1 mm in diameter. To achieve the fine thin strips, the dough is stretched with the help of vegetable oil and then air-dried.

I love somen noodles for their mild flavor and pair beautifully with endless topping choices and broth. Plus, the noodles need to be cooked for just under 2 minutes! That’s a win when you try to minimize your time in the kitchen.

My Favorite Somen Brand

There are many somen noodle brands available, but the one I grew up eating is called Ibonoito (揖保乃糸).

Japanese Somen Ibonoito

You can purchase this brand in Japanese grocery stores (the Ibonoito is a major brand, so you should be able to find it in big Japanese markets) or Amazon or this website.

How to Make Cold Tuna and Tomato Somen

Ingredients You’ll Need

  • Somen noodles
  • Canned Tuna
  • Tomato
  • Shiso (toppings, optional)
  • Condiments: Mentsuyu (noodle soup base), rice vinegar, sugar, sesame oil

Overview: Cooking Steps

  1. Make the tuna tomato topping and the noodle broth by simply combining ingredients together. Refrigerate them until you’re ready to serve.
  2. Cook somen noodles and rinse.
  3. Assemble the chilled noodles and toppings. Pour over the broth and enjoy!
A glass plate containing Cold Tuna Tomato Somen topped with julienned shiso leaves.

Versatile Somen Recipes

The somen noodles taste rather plain, but the true joy comes from their smooth, refreshing, and slurp-worthy texture.

Today I used tuna and tomato, but feel free to change it up with other summer vegetables. Cucumber and eggplant are just as good. Instead of pouring the broth over as I did here, you could serve the broth separately for dipping.

Once you get a hang of it, you can make cold somen with all kinds of ingredients and sauces. It makes one of the perfect weeknight meals for summer. And we can say ‘give me all the noodles, even on a hot day’!

A glass plate containing Cold Tuna Tomato Somen topped with julienned shiso leaves.

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A glass plate containing Cold Tuna Tomato Somen topped with julienned shiso leaves.

Cold Tuna and Tomato Somen

4.76 from 37 votes
This 15-minute Cold Tuna and Tomato Somen is the noodle you need for summertime! With savory tuna, juicy tomatoes, and chilled umami-rich broth, you‘ll be happily slurping away even on a hot day. Best of all, it‘s a breeze to make.

Video

Prep Time: 10 minutes
Cook Time: 5 minutes
Total Time: 15 minutes
Servings: 2

Ingredients
 
 

For the Tuna and Tomato Topping

  • 1 Tbsp rice vinegar (unseasoned)
  • 1 tsp sugar
  • ½ (5-ounce) can albacore tuna (preferably packed in olive oil) (70 g; drained)
  • 1 tomato (4.6 oz, 130 g)
  • tsp freshly ground black pepper
  • 2 tsp toasted sesame oil

For the Somen Noodles

For the Broth

Japanese Ingredient Substitution: If you want substitutes for Japanese condiments and ingredients, click here.

Instructions
 

  • Gather all the ingredients.
    Cold Tuna Tomato Somen Ingredients

To Make Ahead (optional)

  • You can prepare the following steps several hours before you serve. In a medium bowl, combine 1 Tbsp rice vinegar (unseasoned) and 1 tsp sugar and whisk well.
    Cold Tuna Tomato Somen 1
  • To the bowl, add ½ (5-ounce) can albacore tuna (preferably packed in olive oil), including the oil. Mix well with the seasonings.
    Cold Tuna Tomato Somen 2
  • Cut 1 tomato into 8 wedges, then cut each wedge into 3 pieces (about ½-inch (1.3-cm) cubes).
    Cold Tuna Tomato Somen 3
  • Add the tomato cubes into the bowl and season with ⅛ tsp freshly ground black pepper and 2 tsp toasted sesame oil. Toss all together well and keep it chilled in the refrigerator.
    Cold Tuna Tomato Somen 4
  • Cut off the stems of 5 shiso leaves (perilla/ooba) and roll them up from the stem side. Cut them into thin julienned strips.
    Cold Tuna Tomato Somen 5
  • Fluff them up with your fingers and set them aside.
    Cold Tuna Tomato Somen 6
  • Make the noodle broth with ⅓ cup mentsuyu (concentrated noodle soup base) and 1 cup water. Keep it chilled in the refrigerator.
    Cold Tuna Tomato Somen 7

When You Are Ready To Serve

  • Bring a large pot of water to a boil. No need to salt the water for somen noodles. Once boiling, add 7 oz dried somen noodles so they are separated (as you would with spaghetti noodles). Cook according to the package instructions, usually 1½–2 minutes.
    Cold Tuna Tomato Somen 8
  • Keep stirring to make sure the noodles don‘t stick to each other. Control the heat so the water doesn‘t boil over.
    Cold Tuna Tomato Somen 9
  • Once the noodles are done, drain into the colander. Quickly run cold water over the noodles to cool a bit.
    Cold Tuna Tomato Somen 10
  • Once the noodles are cool to the touch, knead/rub the noodles between your hands several times under running water. This helps removing any excess oil from the noodles.
    Cold Tuna Tomato Somen 11
  • Drain well and serve onto individual plates.
    Cold Tuna Tomato Somen 12
  • Top the noodles with the tuna and tomato mixture.
    Cold Tuna Tomato Somen 13
  • Pour the broth over the noodles and garnish with shiso leaves.
    Cold Tuna Tomato Somen 14

To Store

  • If you have extra tuna and tomato mixture and broth (BEFORE serving), save them separately in airtight containers and store them in the refrigerator for 2–3 days. I recommend cooking noodles right before serving so they don‘t stick together.

Nutrition

Calories: 444 kcal · Carbohydrates: 72 g · Protein: 23 g · Fat: 7 g · Saturated Fat: 1 g · Polyunsaturated Fat: 2 g · Monounsaturated Fat: 2 g · Cholesterol: 13 mg · Sodium: 871 mg · Potassium: 219 mg · Fiber: 6 g · Sugar: 15 g · Vitamin A: 562 IU · Vitamin C: 9 mg · Calcium: 30 mg · Iron: 1 mg
Author: Namiko Hirasawa Chen
Course: Main Course
Cuisine: Japanese
Keyword: canned tuna, somen, tomato
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4.76 from 37 votes (32 ratings without comment)
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Is there an option to use something else besides tsuyu or tsuyu that doesn’t have kombu? Looking to avoid kombu ingredient specifically. Thank you!

Hi Vee, Kombu is commonly found in prepared Mentsuyu. What about making your own Mentsuyu?
You can modify Nami’s recipe by substituting 2-3 shiitake mushrooms for the kombu.
https://www.justonecookbook.com/mentsuyu-noodle-soup-base/
We hope this was helpful!

I just finished making this dish! It’s very flavorful and quick without being too pricey. I totally recommend it!5 stars

Hi Marissa! Aww. We are so happy to hear you enjoyed Nami’s Somen recipe.
Thank you so much for trying the recipe, and providing such thoughtful comments.
Happy Cooking!

thanks for the recipe Naomi, gonna try this soon5 stars

Hi JacobSmith! Thank you very much for trying Nami’s recipe!
We hope you enjoy the Cold Somen!🙂

Wonderful, simple and quick recipe. I used campari tomatoes for more tomato flavor and it turned out excellent! I only had mint and it added a light herby flavor that was nice – would suggest adding some type of herb if you have it on hand as I’ve made this recipe without any and it was not as good.5 stars

Hi Brenda! Thank you very much for trying Nami’s recipe and sharing your cooking experience with us!
We are sorry to hear that you missed the Shiso. Many JOC readers grow their own Shiso, and we hope you give it a try one day. https://www.justonecookbook.com/shiso-perilla/
Thank you for your kind feedback.💞

I made this last night with Momotaro tomatoes I bought from Mitsuwa. It turned out to be such a delicious, light and refreshing summer dinner. My picky toddler ate it all up too which shocked me. Thank you!

Hi Wendy! Thank you very much for trying Nami’s recipe and for your kind feedback!
We are so happy to hear you and your family enjoyed this dish! Happy Cooking!🙂

Hi, I have just bought a bottle of concentrated mentsuyu and would be very grateful if you could translate the dilution instructions. I’ve attached an image of the label. Thank you

Hi Sarah! We are happy to help you!
But somehow, the image of the label didn’t attach to your comment. Could you please try again?

Hi Namiko, I ordered the noodles and Kikkonam Hon Tsuyu soup and sauce base from Amazon. There was an “also purchased” for the Tsuyu sauce under the order for the noodles. I have four bottles of the Tsuyu soup and sauce base. What is the dilution factor for the cold Somen noodle dish? Can I use the same dilution for other cold noodle dishes?
Love your recipes they remind me of the years when I traveled to Tokyo and Kyoto in the hot summer months for business. I do not get back to Japan these days so I am learning how to make my own favorite dishes which you supply the recipes.5 stars

Hi William! Thank you very much for reading Nami’s post and for your kind feedback!
There are many types of Tsuyu Sauce. Some of the sauces are concentrated, some are not required to dilute with water.
We are not sure which ones you purchased, but this post might help you.🙂 https://www.justonecookbook.com/mentsuyu/
If you still need help, please send us a photo of the back(label) of the bottle. We will be happy to check it for you!

This was GREAT! Too lazy to hit the market for somen so I used soba. Wonderful5 stars

Hi Dee! Thank you very much for trying Nami’s recipe and for your kind feedback!
We are so happy to hear soba worked well with this dish as well! Happy Cooking!

Thank you. Can’t wait to try. I’ve been curious why you make such small servings. Why only use half a can for 2 servings?

Hi Leigh! Thank you very much for reading Nami’s post and trying her recipe!
We have readers who are single, couples, and large families, so we want to accomplish everyone’s needs.
Please click “serving” so you can adjust the servings amount you prefer. You can also click the X2 or X3 bar at the top of the ingredient list.
We hope this helps!

I think what Leigh means why only using 1/2 canned tuna for 2 noodle servings? it might make more sense to actually use the entire can for making 2 servings. If only for 1 serving, it makes sense to only use 1/2 canned tuna.

Looks like a very refreshing dish! Do you suggest to rub the noodles the same way you did here if I were to make cold udon or soba?
I like cold soba a lot in the summer , usually serve with tofu, cucumbers, pan fried eggs, imitation crab etc

Hi J L, Thank you very much for reading Nami’s post!
Your version of cold soba noodle sounds great too!🙂
Yes, you can rub the udon or soba noodles. It helps to remove coated starch as well.
We hope this helps!