Heat a large nonstick skillet coated with cooking spray over medium-high heat. Add onion, garlic, pork, and chiles; cook 6 minutes or until browned, stirring to crumble.
Place 4 tortillas in a single layer on a baking sheet. Spread about 1/3 cup pork mixture over each tortilla; top each with about 1/3 cup cheese, 1 tablespoon green onions, and 1 tortilla.
Broil quesadillas for 1 1/2 minutes on each side or until crisp. Cut each tortilla into 4 wedges. Serve with sour cream and salsa.