The sandwich is super easy. Spread margarine on one side of two slices of bread (these will be the top and bottom of the sandwich, margarine side out). Spread avocado on one slice of bread (for these we used 1/3 of a whole avocado), topped with minced garlic (or powdered/granulated) and a couple of tomato slices. Add anything else you might want! Warm up your skillet and toss these babies on. They're done in no time!
Another option: instead of spreading margarine on the bread slices, you can just add oil or margarine to the skillet. But I've always preferred it this way ;)