Hiyashi Somen with Light Tsuyu and Summer Toppings

Why You’ll Love This Recipe

• Ultra-refreshing and light—perfect for hot days.
• Ready in 20 minutes using mentsuyu concentrate, or make a fragrant from-scratch tsuyu.
• Clean, balanced flavors with crisp cucumber, zingy ginger, aromatic myōga, and scallions.
• Effortless to scale for a crowd or a simple solo lunch.

Grocery List

• Produce: Fresh ginger, myōga buds, scallions, cucumber, optional shiso leaves, optional citrus (yuzu/sudachi or lime)
• Dairy: None
• Pantry: Dried sōmen noodles, mentsuyu (or soy sauce, mirin, sugar), kombu, katsuobushi, toasted sesame seeds, ice

Full Ingredients

Noodles

• 320 g dried sōmen noodles (about 11 oz; 80 g per person)
• Ice cubes and plenty of cold water for chilling

Light Tsuyu Dip (choose one)

Option A — Shortcut Tsuyu (about 480 ml / 2 cups)

• 120 ml mentsuyu, 3x concentrate (1/2 cup)
• 360 ml ice-cold water (1 1/2 cups)
• Optional: 1 tsp sugar to soften edges

Option B — From-Scratch Light Tsuyu (about 500–600 ml)

• 600 ml water (2 1/2 cups)
• 10 g kombu (dried kelp; about a 10 x 10 cm sheet)
• 15 g katsuobushi (1 loosely packed cup bonito flakes)
• 60 ml soy sauce (1/4 cup)
• 60 ml mirin (1/4 cup)
• 1 tsp sugar (optional, to taste)

Toppings

• 20 g fresh ginger, finely grated (about 1 tbsp packed)
• 2 myōga buds, thinly sliced
• 3 scallions, thinly sliced on the bias
• 1 small Persian cucumber (or 1/2 English), julienned
• Optional: 6 shiso leaves, finely shredded; 2 tsp toasted sesame seeds; shichimi togarashi to taste

Step-by-Step Instructions

Step 1: Chill bowls and set up your ice bath

Place 4 shallow serving bowls and 4 small dipping cups in the refrigerator or freezer for at least 10 minutes. Fill a large bowl with cold water and plenty of ice for shocking the noodles later. Chilled serving ware helps keep the noodles refreshingly cold at the table.

Step 2: Make the tsuyu (choose quick or from-scratch)

For the shortcut: In a jug, combine 120 ml mentsuyu (3x concentrate) with 360 ml ice-cold water. Stir in 1 tsp sugar if desired. Refrigerate until very cold (4–10°C / 40–50°F).

For from-scratch: Add kombu to 600 ml water in a saucepan and soak 10 minutes. Heat gently to 80–90°C (175–195°F); remove kombu just before boiling. Add katsuobushi, turn off the heat, and steep 2 minutes. Strain through a fine sieve or paper towel. Return dashi to the pan with soy sauce, mirin, and optional sugar; bring just to a bare simmer for 1 minute to mellow the alcohol. Cool rapidly by setting the pan in an ice bath, then chill until very cold (4–10°C / 40–50°F).

Step 3: Prepare the toppings

Julienne the cucumber into fine matchsticks. Thinly slice the myōga and scallions. Finely grate the ginger (a microplane works well). Keep everything chilled; you can rest the cucumber and myōga on a small plate with a few ice cubes to keep them crisp.

Step 4: Boil the sōmen briefly

Bring a large pot of water (at least 3 liters / 3 quarts) to a rolling boil. Do not salt the water; the dip is seasoned. Add the sōmen and immediately stir to separate strands. Cook 1 1/2–2 minutes (check your package; sōmen cooks fast). Begin tasting at 1 minute 30 seconds. The noodles should be tender with the slightest bite.

Step 5: Rinse away surface starch and ice-chill

Drain the noodles in a colander. Rinse under strong cold running water for 30–60 seconds, rubbing and agitating the noodles with your fingers to remove starch and cool them. Transfer to the prepared ice bath and chill for 1–2 minutes. Drain very well and shake off excess water; waterlogged noodles dilute the dip.

Step 6: Portion, garnish, and serve

Twirl small nests of noodles onto the chilled plates. Add a few ice cubes around the noodles to maintain temperature. Arrange toppings in small piles or in tiny dishes: cucumber, myōga, scallions, and grated ginger (plus optional shiso and sesame). Pour the cold tsuyu into the chilled dipping cups and set alongside.

Step 7: How to eat

To enjoy, pick up a small bundle of noodles, briefly dip into the tsuyu (about 1–2 seconds), and slurp. Add toppings to each bite as you like. If the tsuyu tastes strong as the ice melts less, stir in a splash of cold water; if it feels light, add a dash more mentsuyu or soy to taste.

Pro Tips

• Use lots of boiling water and stir right after adding sōmen to prevent clumping.
• Rinse vigorously and rub the noodles—this is key to a clean, bouncy texture.
• Keep everything cold: pre-chilled plates, ice bath, and cold tsuyu make the dish shine.
• For crystal-clear tsuyu, keep dashi below a boil and strain through a damp paper towel.
• Grate ginger just before serving for maximum aroma and a gentle heat.

Variations

• Vegetarian/Vegan tsuyu: Make a kombu–shiitake dashi (replace katsuobushi with 2 dried shiitake; soak 30 minutes, heat to 80–90°C, steep 10 minutes) and season as above.
• Protein boost: Add kinshi tamago (paper-thin omelet cut into threads), chilled poached chicken, or boiled shrimp.
• Citrus lift: Finish the tsuyu with a few drops of yuzu or sudachi juice, or serve with lime wedges.

Storage & Make-Ahead

Tsuyu keeps 4–5 days refrigerated in a sealed jar; from-scratch tsuyu can be frozen up to 1 month. Slice toppings the day you serve for best crunch; you can prep scallions up to 24 hours ahead and chill in cold water, then drain well. Cooked sōmen is best eaten immediately. For short holds, keep the noodles in ice water up to 2 hours; drain and shake dry before serving. For next-day use, rinse again in very cold water to refresh, though texture will be slightly softer.

Nutrition (per serving)

Approximate: 320 kcal; 9 g protein; 62 g carbohydrates; 2 g fat; 2 g fiber; 1100 mg sodium (varies with brand of mentsuyu and how much you dip).