SAUCE

2 1/4 cups whole milk

2 tablespoons unsalted butter

2 tablespoons all-purpose flour

2 cups shredded sharp white cheddar cheese (6 ounces)

1/4 cup freshly grated Parmigiano-Reggiano cheese

Pinch of freshly grated nutmeg

Few dashes of hot sauce

Kosher salt

Pepper

SANDWICHES

16 slices of thick-cut bacon

2 tomatoes, cut into eight 1/4-inch-thick slices

1 tablespoon canola oil

Kosher salt

Pepper

Eight 1/2-inch-thick slices of day-old white sandwich bread

4 tablespoons unsalted butter, cut into pieces

2 pounds roast turkey breast, sliced 1/4 inch thick

1 1/2 cups shredded sharp white cheddar cheese (4 1/2 ounces)

1/2 cup freshly grated Parmigiano-Reggiano cheese

Chopped chives and chopped parsley, for garnish