Restaurant's miso soup is usually a bowl of miso flavored broth with 2 or 3 pieces of tofu and green onions. My grandmother's recipe is so much hearty and tasty, she throws in every ingredient available [chicharron miso soup, anyone?] and that's the miso soup I like.
Add-ins and variations: chicken or pork meat, white or black quinoa, almost any kind of vegetable [I've used zucchini, eggplant, spinach, broccoli, chinese cabbage...] —chefpandita
Sautee chopped onion in the oil at low temperature in a medium sized pan. While it cooks, rinse and drain the quinoa.
When the onion is transparent add the minced garlic and cook until fragrant. Add the chopped carrots, quinoa, miso paste and cover with 1L [4 cups] of water.
Leave the pot boiling at medium heat. You might have to add more water while the quinoa is cooking. Since it takes around 15-20 minutes for the quinoa to be cooked; feel free to add the tofu after 10 minutes have passed, so that it absorbs the miso flavor.
When the quinoa’s white germ starts showing, add the chopped veggies reserving the green onions for the end. Taste the broth: if its too salty, add more water. If its bland, add more miso or salt. You could even add a dash of soy sauce!
Cook the veggies for as long as you like [I cook them for 1-2 minutes, I like my veggies to retain their texture] and once you’re ready to turn off the heat, add the green onions.