In a medium saucepan, cover beans with cold water by 2 inches. Add one quarter each of onions and jalapenos and bring to a boil over high. Reduce to a rapid simmer; cook until beans are tender, 45 to 50 minutes. With a slotted spoon, transfer 1 1/2 cups bean mixture to an airtight container. Let cool, then refrigerate, and save for Mushroom and Black Bean Tortilla Casserole.
In a large Dutch oven or heavy pot, heat oil over medium-high. Add garlic and remaining onions; season with salt and pepper. Cook, stirring often, until onions are soft and golden brown, 10 minutes. Stir in remaining jalapenos, cumin, beans and their cooking liquid, and broth. Season with salt and pepper. Bring to a simmer and cook until beans are soft, 20 minutes (if necessary, add up to 1 cup water to keep beans covered).
Transfer 2 cups soup to a blender and add cornstarch. Puree until smooth (use caution when blending hot liquids). Return to pot. Cook, stirring, until soup thickens, 1 to 2 minutes. Add lime juice and season to taste with salt and pepper. To serve, top with avocado, diced onion, cilantro, yogurt, and tortilla strips if desired.
Instead of soaking dried beans overnight, cover them with cold water by 2 inches in a pot; bring to a boil and cook 2 minutes. Remove from heat, cover, and let sit 1 hour. Freeze leftover soup, up to 1 month.
Amazing - Had it this week and it will be making a return appearance. I used canned beans as well and 2 cups of vegetable broth was enough to get it right. It's a filling meatless dish
This is one of my favorite recipes yet! So healthy and so delicious! Even my 8 year old daughter loves it and asks for it in her lunch for school. I use the canned black beans, and substitute 1/2 cup of white wine and 2 1/2 cups of water, instead of 3 cups of just water. I also use a couple extra cloves of garlic. Such a great recipe!!!