1Slice 3 to 4 medium-sized onions as thick or as thin as you want.
2Shred a 16-ounce block of Swiss cheese.
3Dump the sliced onions in a bowl and season them with steak seasoning or beef rub.
4Add two heaping cups of mayonnaise to the bowl.
5Add about a cup of shredded Swiss cheese to the bowl.
6Mix all the ingredients well.
7Add the rest of the cheese and mix again.
8Transfer the mixture into an oven-safe dish.
9Put the dish in the smoker and let it smoke at 300 degrees for about an hour or until it's nice and golden brown and bubbly. If you don't have a smoker, just use your oven.
10Serve it alongside toasted French bread, chips or crackers.