Here’s the correct way to build a burger:
- Toast the buns, but not too much
- Put mayo on the bottom bun, then salt and pepper
- Lettuce goes on next, shredded if you prefer
- Then onions
- Then a large tomato slice
- Then the patty, cheese on top
- Bacon
- Yellow mustard on the top bun sets it all off.
Do not let ketchup anywhere near this culinary perfection. Put it on the side, if you must.