I made my own "healthier" version last night. It goes something like this:
Warmed whole-wheat tortilla
The best tomatoes I could find, given the season
Proscuitto di Parma
Easiest. Meal. Ever. Warm tortilla. Spread one tablespoon of mayo on said tortilla. Lay down arugula, sliced tomatoes, and one to two ounces good proscuitto. Roll and eat.
It really doesn't get any easier--or simpler--than this.