In a bowl, combine tuna, mayo, scallions and red pepper. Heat 1 teaspoon oil a large non-stick skillet on medium. Working with 2 tortillas at a time, cook until beginning to brown, flip and top with half the cheese; cook until melted. Transfer to plates and repeat with remaining teaspoon oil, tortillas and cheese. Divide tuna mixture among tortillas, then top with lettuce and tomatoes and wrap up.