Heat a pan and melt 1 tbsp butter.

Toast the hotteok on both sides until golden brown. Repeat for all 4 pieces.

Cook the eggs to your preference (hard-boiled or soft-boiled).

Cook the beef patties until golden brown on both sides.

Prepare lettuce for layering; no need to chop if using salad-ready lettuce.

Spread mayonnaise on one side of a hotteok.

Layer the beef patty on top of the mayonnaise.

Add a slice of cheddar cheese.

Place the cooked egg on top of the cheese.

Add lettuce on top of the egg.

Spread mustard sauce on the second hotteok.

Place the second hotteok on top to complete the burger.

Wrap the burger in foil or plastic wrap for easier handling.