Soak beans in a jar full of water overnight. Drain beans and pour into a large pot, covering with lots of water, then bring to a boil. Reduce to a simmer and cook, stirring occasionally, until beans are tender. (In my case, it took about 2 hours or so.)
Preparing Bell Peppers:
Cut peppers in half and remove seeds, stems and membranes. Place skin-side up on a foil-lined baking sheet and broil until blackened - about 12 minutes. Place in a paper bag and let stand for 10 minutes. Peel away the blackened skin and chop finely.
Preparing the Chili:
Heat oil in a large pot over low to moderate heat. Add onion and cook for 10 minutes until nicely browned. Stir in cumin, crushed chili flakes, paprika(s), a pinch of salt and garlic, plus a splash of white wine, then cook for 2 minutes. Add peppers, broth, squash and tomatoes, bring to a simmer and cook, stirring occasionally, for about 20 minutes. Add cooked beans and continue simmering for an additional 25 minutes. Puree about a third to a half of the chili using an immersion blender or blender/processor to make it thick and tasty. Serve with sour cream.
Obviously you can use whatever mixture of dried beans you like. Or, you can use canned - the ratio is 1/2 cup dried beans (makes approximately 1 1/2 cups cooked) to 1 15oz can of drained, canned beans.
Or, you can use about 4 canned roasted red peppers. Sometimes red bells are just too expensive to buy here, so I always have some canned on hand.
In this case, I used acorn, but you could use butternut, delicata, hubbard or even pumpkin. Or just about any other winter squash I've forgotten to name here, except maybe spaghetti squash. That I don't think would work.
I use the overnight soaking method, but you can also do a "quick soak." I don't like it because it's more work and takes just as long as the overnight soaking method! It's really only useful when you forget the put the beans in a jar the night before.