Method
Heat vegetable oil in large skillet over medium-high heat. Add mushrooms, bell pepper and garlic; cook, stirring constantly, for 1 to 2 minutes. Add spinach; cook just until spinach is wilted.
Spread half of mixture onto one tortilla; sprinkle with half of cheese. Place second tortilla evenly over mixture.
Melt margarine in large skillet over medium-high heat. Place quesadilla in skillet; cook for 1-2 minutes on each side or until golden brown and cheese is melted.
Repeat with remaining ingredients. Top with salsa.