Sort and wash Anasazi beans; place in a large bowl. Cover with water to 2 inches above beans. Repeat procedure with black beans. Cover and let stand 8 hours or overnight. Drain separately.
Place Anasazi beans in a large saucepan; cover with water to 3 inches above beans. Bring to a boil. Reduce heat; simmer 50 minutes or until tender. Drain. Repeat procedure with black beans.
Heat a large Dutch oven over medium-high heat. Coat pan with cooking spray. Add onion and next 5 ingredients (through garlic); sauté 6 minutes or until tender. Add beans, broth, and next 5 ingredients (through tomatoes); bring to a boil. Cover, reduce heat, and simmer 15 minutes. Stir in chorizo; simmer 15 minutes. Serve with sour cream and chopped onion, if desired.
Beer note: A Mexican dark lager, like Negra Modelo ($8/6-pack), offers a heartiness that makes it ideal with chili. This beer's chocolate flavors are perfect with smoky beans, while a touch of caramel sweetness provides a balance for spicy sausage and chiles. —Jeffery Lindenmuth