Prep the filling

• Finely dice the onion.
• Shred the lettuce and slice the tomato.
• Warm the flour tortillas so they stay pliable.

Sear the beef

• Heat the vegetable oil in a hot skillet or on a flat griddle.
• Add the ground beef in loose chunks and press down to get a crust.
• Season with salt, black pepper and garlic powder.

Chop and melt the cheese

• Add the diced onion to the beef.
• Chop and mix everything together with a spatula until well combined.
• Lay the American cheese slices over the meat and let them melt into the mixture.

Build the burrito

• Spread mayonnaise and ketchup over each warm tortilla.
• Spoon the chopped cheese mixture down the center.
• Top with shredded lettuce and sliced tomato.
• Fold in the sides and roll the tortilla tightly into a burrito.

Toast and serve

• Place the burrito seam-side down on the hot griddle.
• Toast until golden and crisp on both sides.
• Slice in half and serve hot.