Prepare your ingredients (cut your tomatoes, lettuce leaves, onions, buns, cheese).
Organize your workplace (systematically arrange the ingredients, equipment and tools around your grill)
Season your burger patties (salt, pepper, olive oil)
Put the patties on a hot grill (and don't move them for 2,5 - 3,0 minutes)
Add the bottom halves of the bun on the grill, once they're done take them off.
Start building layers - bottom bun half, mustard mayo, fresh lettuce, tomato, + the slice of cheese.
Turn your burgers around (one side should be done by now). Season with salt and pepper.
After a minute, put cheddar cheese on the burger patties, while they're still on the grill.
Put the onions on the grill.
Put the upper halves of the bun on the grill.
Take off the burger patties and put them directly on the top layer of your so-far build burgers.
Put the grilled onions on as the next layer.
And lastly, put the upper halves of the bun (which should still be hot) on the very top.
Make your burgers stand together with hamburger BBQ skewers sticks.
Serve and eat. Delicious!