Spread the sauce on one side of one slice of bread. Top with basil leaves (if desired), roasted bell peppers, and cheese slices and cover with a second slice of bread.
Lightly brush both sides of the sandwich with olive oil.
Preheat a nonstick skillet well over medium heat. Cook the sandwich for 4-5 minutes on each side (until the bread is browned and the cheese is melted). Cut the finished sandwich in half.