Method

Spread half the mayo on each slice of bread; repeat with mustard. If using avocado, cut into thin slices and lay on what will be the bottom piece of bread. Now lay on the grilled onion, cheese, meats, pickles, tomato and lettuce, with the optional bacon on the very top. Make sure to arrange your ingredients evenly over the previous layer so that every bite has a bit of each item. If you like, you can sprinkle some salt and pepper over the tomato, especially if you leave out the pickles. Cover with second slice of bread, mayo side down. Push two big frilled toothpicks through the sandwich (one on each half), cut sandwich in half, and serve immediately, with a side of potato chips and pickles, if desired.