You can fill your sandwich with avocado, tomato, healthy meat of choice, an artisanal hard cheese such as parmesan, asiago or gruyere, heathy mayo, salt and pepper to taste. To make mayo, simply blend 1 whole egg, 1 tablespoon lemon juice, salt and pepper while slowly adding 1 cup of olive oil, macadamia nut oil, or avocado oil (you'll see it thicken as you add oil).  Due to the added carbohydrate content, sandwiches should be consumed on higher volume workout days only.