On three of the tortillas, spread the Thai peanut sauce. Then layer with sausage, onion, peppers and cheese. Cover with the remaining tortillas. Melt one T. butter in large non-stick fry pan. Place one quesadilla in pan and heat until cheese begins to melt over medium low heat. Add 1 T. butter as you turn quesadilla over with large spatula to heat the other side until completely heated through and nicely browned. Repeat with remaining quesadillas. Serve hot. Cut each in half for individual servings or in 6- 8 pieces each for appetizers.