Steps
1. Preheat your grill or stovetop skillet over medium-high heat.
2. Season the ground beef patty with salt and pepper on both sides.
3. Cook the patty on the grill for about 3-4 minutes on each side for medium doneness.
4. In the last minute of cooking, place the slice of cheddar cheese on top of the patty to melt.
5. While the burger is cooking, toast the hamburger bun on the grill or in a toaster.
6. Assemble the burger by placing the lettuce on the bottom bun, followed by the tomato, burger patty with melted cheese, red onion, ketchup, and mustard.
7. Top with the other half of the bun and serve immediately.