spicy black bean soup... 1 hour and 45 minutes (plus soaking)

the goods:

1 pound dried black beans, picked over, soaked overnight, and drained
2 large yellow onions, diced small
2 jalapenos, minced
1 tablespoon extra-virgin olive oil
4 garlic cloves, minced
2 teaspoons ground cumin
1 and 3/4 cups low-sodium vegetable broth
1 tablespoon cornstarch
2 tablespoons fresh lime juice
diced avocado, cilantro, sour cream, and tortilla chips for serving

In a medium saucepan, cover beans with cold water by 2 inches. Add one quarter each of onions and jalapeno 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 and 1/2 cups bean mixture to a tupperware. Let cool, then refrigerate for Mexican lasagna tomorrow night. 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 jalapeno, 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. Transfer 2 cups soup to a blender and add cornstarch. Puree until smooth. 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, cilantro, sour cream, and tortilla chips if desired.