In a large skillet, saute onion and garlic in butter until tender. Add spinach and pepper; cook for 2-3 minutes or until heated through. , Place about 3 tablespoonfuls off center on each tortilla; top with 1 tablespoon picante sauce and 2 tablespoons cheese. Fold sides and ends over filling and roll up., Place seam side down in a 13x9-in. baking dish coated with cooking spray. Top with remaining picante sauce and cheese. Bake, uncovered, at 350° for 20-25 minutes or until sauce is bubbly and cheese is melted.