Toast the buns

• Spread the butter on the cut sides of the buns
• Toast them in a hot pan until golden, then set aside

Smash the patties

• Place the beef balls in the very hot pan
• Press each one down firmly with the spatula until thin and flattened
• Season with salt and pepper

Sear and add the cheese

• Flip the patties once a crust has formed
• Lay the cheddar slices on top so they melt

Assemble the burger

• Spread burger sauce on the bottom bun
• Stack the patties with the cheese, onion and pickles
• Close with the top bun and serve immediately