In a small bowl, mix together the mayonnaise, relish, ketchup, sugar, and vinegar. Set aside.

Weigh out 8 portions of 3.5 oz of ground beef or eye it out. Gently flatten the patty into a circle to desired thin or thickness, making sure to not mix or mold it too much. Sprinkle with salt and pepper on both sides. Set aside.

Brush the insides of the buns with butter.

Heat a pan or skillet over medium heat. Lay the buns butter side face down. Take them off the pan when a nice golden brown develops around the edges.

Over medium-high heat in a skillet or pan, add 1/2 a tablespoon of butter and 1/2 a tablespoon of vegetable oil. Add the patties in, two at a time or more if you have a large grill/skillet. Add a teaspoon of mustard on the raw side and spread evenly. It will take about 2-3 minutes for the patty to get a nice brown crust. Flip over and add a slice of American cheese on top of half the patties you cook since Big Macs only have 1 cheese but 2 patties. Let it cook for about 1 more minute for the cheese to melt. Take off the heat.

To the bottom bun, add sauce, lettuce, onion, patty, and cheese. Then add the middle bun, sauce, lettuce, onion, pickles, and the second patty. Add the top bun.

Enjoy warm!