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.
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; saut 5 minutes. Stir in garlic; saut 1 minute. Stir in tomato paste; cook 2 minutes, stirring frequently.
Add chili powder, oregano, coriander, and cumin; saut 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.