BROTH: Heat a large pot or dutch oven over medium-high heat. Add a little water (or sub oil) and onion, garlic, ginger, celery, and carrot. Season with a bit of salt and pepper and sauté for 4-5 minutes.
Add bell pepper, cabbage, and curry powder and stir. Sauté for 3 minutes, then add kombu, shiitake mushrooms, kale stems, salt and pepper, nutritional yeast (optional), and water.
Bring to a low boil over high heat, then reduce to a simmer, cover, and cook for at least 30 minutes, preferably 1 - 1 ½ hours.
Season to taste with more salt and black pepper. Then, 1) serve as a vegetable soup, 2) strain and use as a broth (cool and store leftovers in the refrigerator for 5 days, or in the freezer for 3 months), or 3) strain and make a tonic with miso.
TONIC: To make a serving of miso tonic, add 2 tsp miso paste to a serving bowl and add a bit of the broth. Stir to combine. Then add ~1 cup broth and stir to combine (add more broth for a less potent miso flavor, less broth for a more potent miso flavor). Then add a bit of chopped green onion and serve. Best when fresh but will keep in the refrigerator for 2-3 days. Though not ideal for reheating because the aromatic qualities and nutritional benefits of miso are damaged when boiled.
*If adjusting batch size, tonic measurements in ingredient list will not accurately reflect 1 serving of tonic. Follow instructions section instead. *Nutrition information is a rough estimate calculated for 1 tonic without straining and without optional ingredients. *This is not a traditional miso soup, but rather a gut-calming tonic with miso. For a traditional take on miso soup, check out this recipe by Just One Cookbook.