This miso soup with prawns and eggplant elevates the classic Japanese comfort food into a satisfying meal. Silky baby eggplant, succulent prawns, and crisp Asian greens swim in an umami-rich dashi broth finished with sweet white miso. It's restaurant quality in just 20 minutes.
While basic miso soup is often a simple starter, this version stands alone as a light, healthy dinner. The combination of protein-rich prawns and tender vegetables makes it surprisingly filling despite its low calorie count.
Understanding Miso: Fermented Magic
Miso paste is one of the world's great fermented foods. Made from soybeans, salt, and koji (a beneficial mold), miso develops complex flavors during months or years of fermentation. The result is an ingredient packed with umami - that savory "fifth taste" that makes food deeply satisfying.
For this soup, use white miso (shiro miso). It's fermented for a shorter time than red miso, giving it a milder, sweeter flavor that complements delicate prawns without overwhelming them. White miso also has a lighter color that keeps the soup beautifully pale.
The Golden Rule: Never Boil Miso
This is the most important rule of miso cooking: never boil miso. Boiling destroys the delicate flavor compounds that make miso special. It also kills the beneficial probiotics that contribute to gut health.
Always remove your pot from heat before adding miso. Dissolve the paste in a small amount of warm broth first (this prevents clumps), then stir it back into the soup. If reheating leftovers, warm gently without reaching a simmer.
The Foundation: Dashi Stock
Dashi is the backbone of Japanese cuisine - a light, clear broth that provides umami depth without heaviness. Traditional dashi combines:
- Kombu (dried kelp): Provides glutamates - natural umami
- Katsuobushi (bonito flakes): Adds smoky, fishy depth
For convenience, use instant dashi powder (hon-dashi) - just dissolve in hot water according to package directions. It's what most home cooks in Japan use. For the purist approach, make dashi from scratch by steeping kombu and bonito flakes.
Why Baby Eggplant?
Baby eggplants are perfect for soup because they:
- Cook quickly without becoming mushy
- Have tender, edible skin
- Are less bitter than large eggplants
- Turn silky and almost creamy when cooked
Look for Asian varieties like Japanese or Thai eggplants - they're smaller and more tender than Italian globe eggplants. Slice them into 1cm rounds so they cook evenly.
Cooking Prawns Perfectly
Prawns cook in just 2-3 minutes. They're done when they turn from translucent grey to opaque pink and curl into a loose "C" shape. Overcooked prawns become rubbery, so watch them carefully and remove from heat as soon as they're done.
Add prawns after the eggplant is nearly cooked - this ensures everything finishes at the same time.
The Finishing Touches
Fresh garnishes are essential to miso soup:
- Green onions: Add fresh, sharp flavor and bright color
- Toasted sesame seeds: Provide nutty crunch and visual appeal
- A drizzle of sesame oil: Optional, but adds richness
Miso Soup with Prawns and Eggplant
Quick, umami-rich, and deeply satisfying Japanese comfort food.
Nutrition per serving
Ingredients
Instructions
- Heat the dashi. Bring dashi stock to a gentle simmer in a large pot over medium heat. If using instant dashi, dissolve the powder in the water first. Do not let it boil.
- Cook the eggplant. Add eggplant slices to the simmering dashi. Cook for 5 minutes until tender and slightly translucent. The eggplant should be silky but not falling apart.
- Add the prawns. Add prawns to the pot and cook for 2-3 minutes until they turn pink and curl into a loose "C" shape. Don't overcook or they'll become rubbery.
- Add the greens. Add chopped Asian greens and cook for just 1 minute until wilted but still bright green.
- Dissolve the miso. Remove pot from heat immediately. Place miso paste in a small bowl. Add a ladleful of hot broth (about 1/2 cup) and whisk until the miso is completely dissolved and smooth - no lumps.
- Finish and serve. Pour the dissolved miso back into the pot and stir gently. Add soy sauce and stir to combine. Ladle into bowls immediately. Top with sliced green onions and a sprinkle of toasted sesame seeds. Serve right away.
Recipe Notes
- Make authentic dashi: Soak 10cm kombu in 4 cups cold water for 30 minutes. Heat until almost boiling, remove kombu. Add a handful of bonito flakes, steep 5 minutes, strain.
- Add silken tofu: Cut 150g silken tofu into 2cm cubes and add with the greens for extra protein.
- Vegetarian version: Use vegetable dashi (kombu only) and substitute tofu for prawns.
- Storage: Best served immediately. If you must store, keep broth and miso separate - add miso when reheating.
- Reduce sodium: Use low-sodium miso or reduce the amount to 2 tablespoons.
Frequently Asked Questions
Why should I never boil miso soup?
Boiling destroys miso's delicate flavor compounds and kills the beneficial probiotics that make it healthy. Always remove the pot from heat before adding miso, and only warm through gently. If reheating, keep the temperature below a simmer.
What is the difference between white and red miso?
White miso (shiro miso) is fermented for a shorter time, making it milder, sweeter, and lighter in color. Red miso (aka miso) is aged longer, resulting in a stronger, saltier, more complex flavor. White miso is ideal for delicate dishes like this prawn soup, while red miso suits heartier preparations.
How do I make dashi stock at home?
Traditional dashi combines kombu (dried kelp) and bonito flakes (katsuobushi). Soak a 10cm piece of kombu in 4 cups cold water for 30 minutes. Heat gently until just before boiling, remove kombu. Add a handful of bonito flakes, turn off heat, and steep 5 minutes. Strain through a fine sieve.
Can I use regular eggplant instead of baby eggplant?
Yes, slice regular eggplant into 1cm half-moons. Baby eggplants are preferred because they're more tender, less bitter, and have thinner skin that becomes silky when cooked. If using regular eggplant, you may want to salt and drain the slices first to remove bitterness.
Is miso soup healthy?
Miso soup is very healthy - it's low in calories, high in protein from the prawns, and contains probiotics from fermented miso. It's also a good source of B vitamins, minerals, and antioxidants. The sodium content is moderate, but can be reduced by using less miso.
