Simmered Okinawan Purple Sweet Potato and Miso Soup
A nourishing soup featuring Okinawan purple sweet potatoes simmered in a savory miso broth, offering a colorful twist on a Japanese classic. This japanese-inspired soups (vegetarian) ready in about 30 minutes pairs peeled and diced purple sweet potato, dashi stock, white miso paste for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 150 calories and feeds 3, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.
Ingredients
- 200 g, peeled and diced purple sweet potato
- 4 cups dashi stock
- 3 tbsp white miso paste
- 100 g silken tofu, cubed tofu
- 1 tbsp dried wakame seaweed
- 1 stalk, thinly sliced green onion
Instructions
- Step 1: Peel and dice 200 g purple sweet potato into 1/2-inch cubes. Soak 1 tbsp dried wakame seaweed in cold water for 5 minutes to rehydrate.
- Step 2: In a medium saucepan, bring 4 cups dashi stock to a gentle boil over medium heat. Add the diced sweet potatoes and simmer for 12-15 minutes until tender.
- Step 3: Lower heat to low and whisk 3 tbsp white miso paste with a ladle of hot broth in a small bowl until smooth. Stir this miso mixture back into the pot gently, avoiding boiling to preserve flavor.
- Step 4: Add 100 g silken tofu cut into cubes and the soaked wakame seaweed to the soup. Heat through for 2-3 minutes.
- Step 5: Remove from heat and garnish with 1 thinly sliced green onion stalk before serving warm.
Equipment for this recipe
Top-rated tools to make this recipe successfully.
Frequently asked questions
How long does Simmered Okinawan Purple Sweet Potato and Miso Soup take to make?
Total time is about 30 minutes (10 min prep + 20 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.
How do I store leftover Simmered Okinawan Purple Sweet Potato and Miso Soup?
Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep dashi stock from drying out.
Can I substitute ingredients in Simmered Okinawan Purple Sweet Potato and Miso Soup?
Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.
How do I scale Simmered Okinawan Purple Sweet Potato and Miso Soup for a different number of people?
The recipe is written for 3 servings. Multiply each ingredient by (your serving target / 3). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.
Is Simmered Okinawan Purple Sweet Potato and Miso Soup vegetarian?
Yes — this recipe is tagged vegetarian based on its ingredient list. Always cross-check labels for packaged ingredients (sauces, broths, condiments) since formulations vary by brand.
