All American Patty Melt

1 TBS butter
1 sm onion, sliced into thin rings
1 lb ground turkey or ground beef
cooking spray
8 slices sourdough bread
8 slices cheddar cheese
thin slices tomato

Melt the butter in skillet; cook onions until lightly browned; remove and set aside. Make ground meat into 4 patties and cook in skillet until browned and cooked through. In a separate skillet or griddle, spray cooking spray evenly over cooking surface, and put down 4 pieces of the bread. Place a slice of cheese on each bread, then the patty, the onion, the tomato, and another piece of cheese, then place another piece of bread on top of each sandwich. Lightly brown each side, just like a grilled cheese sandwich and serve warm.