Here is how to make a big mac at home:

McDonald's Big Mac
1 regular sized sesame seed bun
1 regular sized plain bun
2 previously frozen regular beef patties
2 tablespoons Big Mac sauce
2−teaspoons reconstituted onions
1 slice real American cheese
2 hamburger pickle slices
1/4 Cup −shredded iceberg lettuce
Discard the crown half of the regular bun, retaining the heel. The cooking
method for the Big Mac is basically the same as the regular burgers, only
the bun toasting method is slightly different. In the Big Mac's case you
toast the bottom (heel) first. Do this along with the extra heel. (this will
be your middle bun.) You can use the crown (top) as the middle bun also,
just cut the rounded side off. However you will have to toast both sides of it.
Cook the two−all−beef−patties just like the regular burgers. After the bun
parts are toasted, put 1 tablespoon of "Mac sauce" on each of the
heels.(toasted side.) Then add 1/8 cup shredded lettuce to each.On the true
bottom bun, place one thin slice of American cheese on top of the lettuce.
On the extra "heel", the middle bun, place two pickle slices on top of the
lettuce. Toast the "crown" (top) of the bun also. When the meat patties are
done, place them one at a time on both prepared buns. Stack the middle bun
on top of the bottom bun, and put the crown on top.