American Cheeseburger

Finely chop the white onion. Wash, dry, and remove the leaves from the parsley, then finely chop it as well. Afterwards, slice the red onion into fine rings and set aside. For the sauce, whisk together 1 tsp mustard, vinegar, egg yolk, salt, and pepper. Then gradually add 8 tbsp sunflower oil while continuously stirring. Afterwards, stir in half of the already chopped onions and half of the chopped parsley.

Now, vigorously knead the ground beef with 1 tbsp mustard, breadcrumbs, salt, pepper, and the remaining half of the diced onions, then form into 4 patties. Heat 2 tbsp sunflower oil in a pan and fry the patties for 8 to 10 minutes, turning regularly.

Wash and dry the lettuce. Also wash the tomatoes and slice them. Then slice the burger buns horizontally and toast them beforehand. Now place the romaine lettuce on the bottom, already toasted burger bun. Then layer the patty on top. On this patty, in turn, place a slice of Gouda. Afterwards, arrange the ketchup and red onion rings along with the mixed sauce. Place the tomato slice on top, to finally close with the upper bun half.