Four-Cheese Grilled Cheese Sandwich

Step 1
Mix butter and garlic in a small bowl until well combined. Spread 1/2 of the butter onto one side of each slice of bread; set aside.

Step 2
Heat 1 tablespoon oil in a large skillet over medium-low heat; stir in spinach and giardiniera. Saute until spinach is wilted and mixture is heated through, 3 to 5 minutes. Remove to a bowl and wipe out the skillet.

Step 3
Place 1 slice of bread, buttered-side down, into one side of the warm skillet. Heat 1/2 tablespoon oil in the other side of the skillet. Place mozzarella slices in the skillet and cook until soft, 1 to 2 minutes. Place mozzarella slices on top of the bread in the skillet. Repeat with the provolone, Asiago, and Fontina slices.

Step 4
Add spinach mixture and tomato slices to the skillet, adding more oil if necessary, and cook until warm, 2 to 3 minutes. Place spinach mixture on top of the cheese, followed by the tomatoes and the remaining slice of bread, buttered-side up. Flip the sandwich and cook until browned and cheese has melted, 5 to 10 minutes.