As appeared in the St. Louis Post-Dispatch
Serves 4
5 tablespoons unsalted butter
8 oz. white mushrooms, trimmed and sliced thin
1 Melissa’s shallot, minced
1/2 teaspoon salt
1/4 cup (4 tablespoons) all-purpose flour
2 cups whole milk
8 ounces sharp cheddar cheese, shredded (2 cups)
2 teaspoons Dijon mustard
2 teaspoons Worcestershire sauce
1/2 teaspoon pepper
4 (3/4-inch-thick) slices rustic white bread
8 ounces thinly sliced roast turkey
8 ounces thinly sliced deli ham
2 tomatoes, cored, cut into 8 (1/4-inch-thick) slices, and patted dry
Melt 1 tablespoon butter in large saucepan over medium-high heat. Add mushrooms, shallot, and salt and cook, stirring occasionally, until well browned, 5 to 7 minutes. Transfer to bowl.
Melt remaining 4 tablespoons butter in now-empty saucepan over medium heat. Stir in flour and cook for 1 minute. Slowly whisk in milk and bring to simmer. Reduce heat to low and cook, stirring occasionally, until thickened, 4 to 6 minutes. Off heat, stir in 1/2-cup cheddar, mustard, Worcestershire, and pepper; set aside.
Adjust oven rack 5 inches from broiler element and heat broiler. Line rimmed baking sheet with aluminum foil and spray with vegetable oil spray. Arrange bread slices on prepared baking sheet and broil until toasted, 1 to 2 minutes per side.
Place bread slices into individual au gratin dishes. Divide mushroom mixture among toasted bread slices. Arrange 2 ounces turkey, 2 ounces ham, and 2 slices tomato over mushrooms on each slice of toast. Spoon 1/2-cup cheese sauce evenly over each sandwich and sprinkle with remaining 1 1/2 cups cheddar. Broil until cheddar is browned, 3 to 5 minutes. Let cool for 5 minutes. Serve.