1. Combine chiles and stock in a microwave-safe bowl; microwave at HIGH 3 minutes. Let stand 10 minutes. Remove stems. Combine chile mixture and mushrooms in a blender; process until smooth.
2. Heat a Dutch oven over high heat. Coat pan with cooking spray. Add bison, 1/2 teaspoon salt, and 1/2 teaspoon black pepper; cook 6 minutes or until browned, stirring to crumble. Remove bison from pan. Reduce heat to medium-high. Add onion and bell pepper to pan; sauté 5 minutes. Stir in garlic; sauté 1 minute. Stir in tomato paste; cook 2 minutes, stirring frequently. Add chili powder, oregano, coriander, and cumin; sauté 30 seconds. Return bison to pan. Stir in beer; cook 3 minutes or until liquid is reduced by half. Stir in mushroom mixture and tomatoes; bring to a simmer. Reduce heat, and simmer 25 minutes. Stir in squash and chickpeas; simmer 45 minutes. Stir in 1/2 teaspoon salt and 1/4 teaspoon black pepper. Top with sour cream and parsley.