I found this in a Taste of Home Cooking For 2 magazine. It can easily be doubled if you need to serve more. The marinade is wonderful and really adds a punch to a plain Portobello buger. I have made these on a gas grill and on a Foreman grill and they were great both ways. This is also great with smoked Gouda cheese in place of the provolone. Prep time does not include the 15 minutes marinating time.