Place 1 flour tortilla in a small lightly greased nonstick skillet. Sprinkle with 2 tablespoons each of shredded cheeses. Spread with 1 tablespoon chiles; sprinkle with 3 tablespoons tomatoes. Top with 1 tortilla, and coat with cooking spray.
Cook quesadillas over low heat 2 to 3 minutes on each side or until golden. Remove from skillet; keep warm.
Repeat procedure with remaining tortillas, cheeses, chiles, and tomatoes. Cut each quesadilla into 6 triangles. Serve with sour cream and salsa.