Spread the mayo on both slices of bread evenly.
Add a pinch of salt and pepper to both slices.
Add 1 piece of turkey, 1 piece of ham and 1 piece of roast beef on each slice of bread.
Add the slice of American cheese to one of the slices of bread.
Add slivers of fresh-cut onion to the slice with the cheese then top with plenty of lettuce (and or use fresh spinach for a pop of color and nutritional value).
Add a fresh tomato slice on top of the lettuce.
Put the two sides together and slice on the diagonal. Lunch is ready!
For a warm treat (if you have an extra few minutes to spare), toast the sandwich in the toaster oven or oven for a few minutes before you add the onions, tomatoes and lettuce.
To make it 'to go', just put it in a baggie, sandwich-sized Tupperware, or wrap in parchment paper and plastic wrap!
