All beef patty
Green leaf lettuce
Mayonaise - ALOT
Ketchup - a couple of drops for flavor (ketchup has a lot of carbs even the less sugar and salt ones)
Mustard - a couple of drops for flavor (Swedish mustard tends to be on the sweeter side)
You can use the lettuce leaves to wrap up the burger to hold it, or use a fork and knife to eat it.
We were lazy and super hungry yesterday so we bought frozen beef burger patties. I was glad I looked at the carb info since the ones we usually buy had 6g of carbs per 90g patty. I found a Tulip brand American Size all beef 110g patty with 0g carbs in it. So we went with that one, and it was really good.