Preheat the oven to 100 C°.
STEP 1
Grill or fry the burger for 1 minute and 15 seconds on each side with a little oil over medium heat.
STEP 2
Cut the buns in half and heat in the oven for a few minutes.
STEP 3
Fry the onion rings in a little cooking oil until lightly browned.
STEP 4
Mix the mayonnaise with the mustard. Take the bottom of the bun, add mustard mayonnaise, pickle, burger, tomato slices, fried onion rings and a little ketchup. Top with lettuce and close with the top of the bun.