1. Preheat oven to 450 degrees. Brush a rimmed baking sheet with oil. In a small bowl, mix together the mustard and ketchup.
2. In a medium bowl, combine beef, egg, panko, 1/2 cup cheddar, 1/2 teaspoon salt, and one teaspoon pepper. Form into four 2-by-4 inch loaves; place on baking sheet. Brush with the mustard mixture, top with remaining 1/2 cup cheddar.
3. Place meatloaves in the oven. Bake until loaves are cooked through, 15 to 20 minutes. Remove loaves from the oven. Cover with foil for 5 minutes before serving.
Source: marthastewart.com