Preparation Melt 2 tablespoons butter in small saucepan over medium heat. Add flour and stir 1 minute. Gradually whisk in milk. Add nutmeg and bay leaf. Increase heat to medium-high and boil until sauce thickens, whisking constantly, about 2 minutes. Season with salt and pepper. Preheat broiler. Place 2 bread slices on work surface. Top each with half of ham and sliced Gruyère. Top with remaining bread. Heat heavy large skillet over low heat. Brush sandwiches with 1 tablespoon melted butter. Add to skillet and cook until deep golden brown, about 2 minutes per side. Transfer to small baking sheet. Spoon sauce, then grated cheese over sandwiches. Broil until cheese begins to brown, about 2 minutes.
Preparation Melt 2 tablespoons butter in small saucepan over medium heat. Add flour and stir 1 minute. Gradually whisk in milk. Add nutmeg and bay leaf. Increase heat to medium-high and boil until sauce thickens, whisking constantly, about 2 minutes. Season with salt and pepper. Preheat broiler. Place 2 bread slices on work surface. Top each with half of ham and sliced Gruyère. Top with remaining bread. Heat heavy large skillet over low heat. Brush sandwiches with 1 tablespoon melted butter. Add to skillet and cook until deep golden brown, about 2 minutes per side. Transfer to small baking sheet. Spoon sauce, then grated cheese over sandwiches. Broil until cheese begins to brown, about 2 minutes.