Cook the beef patties on the pan until browned and cooked through. Place a cheese slice on top of the beef patties and let melt a few seconds

Slice one burger bun in half, apply butter, pan fry inner side until golden or you can just use the buns without frying

Place the beef patties and cheese on top of the burger bun, add sliced cucumber and shredded lettuce. Spread mustard on top and place the top bun. Enjoy