Grilled Sausage Sandwiches With Caramelized Onions & Gruyere Cheese

Step 1: Heat 2 tablespoons oil in heavy large skillet over medium-high heat. Add onions and saute until slightly softened, about 5 minutes. Stir in vinegar, sugar and caraway seeds.

Step 2: Reduce heat to medium-low and saute until onions are deep brown and very tender, about 20 minutes longer.

Step 3: Season to taste with salt and pepper. (Can be prepared 2 hours ahead. Let stand at room temperature. Rewarm over low heat before using.)

Step 4: Preheat broiler.

Step 5: Brush 11x7-inch metal baking pan with oil. Place sausages in pan.

Step 6: Broil until sausages are brown and crisp, about 6 minutes per side.

Step 7: Transfer sausages to work surface and cut lengthwise in half.

Step 8: Arrange 3 sausage halves on each of 2 bread slices.

Step 9: Spread 2 teaspoons mustard over sausages on each.

Step 10: Top sausages with caramelized onions, dividing equally.

Step 11: Top with Gruyere or Emmental cheese slices, dividing equally. Cover with remaining 2 bread slices. Spread half of butter over upper bread slices.

Step 12: Heat large nonstick skillet over medium-low heat.

Step 13: Carefully invert sandwiches, buttered side down, into skillet.

Step 14: Cover and cook until bottoms are brown, about 5 minutes.

Step 15: Spread remaining butter over upper bread slices.

Step 16: Turn sandwiches, cover and cook until bottoms are brown, about 4 minutes longer.