Step 1: Preheat your broiler to high. Lightly butter one side of each bread slice with the softened butter. Toast the bread in a toaster or under the broiler (butter-side up) until lightly golden. Set aside.
Step 2: Prepare the Mornay Sauce: In a medium saucepan, melt 2 tablespoons of butter over medium heat. Whisk in the flour and cook for 1-2 minutes, stirring constantly, to create a roux. Do not let it brown.
Step 3: Gradually whisk in the warm milk, a little at a time, ensuring no lumps form. Continue to whisk until the sauce thickens and comes to a gentle simmer. Cook for 2-3 minutes, stirring, until the raw flour taste is cooked out.
Step 4: Remove the saucepan from the heat. Stir in the salt, white pepper, nutmeg, and shredded Gruyère cheese until the cheese is completely melted and the sauce is smooth and creamy.
Step 5: Assemble the Hot Browns: Place two slices of toasted bread on each individual oven-safe dish or gratin dish. Arrange a generous amount of sliced turkey over the bread.
Step 6: Ladle a generous amount of the warm Mornay sauce over the turkey and bread, ensuring everything is well-covered.
Step 7: Place the dishes under the preheated broiler for 2-5 minutes, or until the sauce is bubbly, golden brown, and slightly caramelized. Watch carefully to prevent burning.
Step 8: Remove from the broiler. Crisscross two slices of crispy bacon over each Hot Brown. Garnish with a sprinkle of paprika and cherry tomato halves, if desired. Serve immediately and enjoy your delicious hot brown recipe Kentucky!