Portobello-Prosciutto Burgers

Rinse mushrooms thoroughly. Soak in red wine for 20 to 30 minutes (this is totally optional!) Combine mayonnaise and basil in a food processor or blender. Pulse until basil is totally mixed in with the mayonnaise. Set aside. Grill mushrooms in a grill pan or on a charcoal grill, brushing lightly with olive oil and sprinkling with salt and pepper. Melt provolone cheese over the four largest mushrooms. Remove mushrooms from grill and stack the other four mushrooms on top of the cheese-topped mushrooms. Drizzle griddle with olive oil. Toast kaiser rolls over medium-low heat until very crispy and toasted. Spread basil mayonnaise generously on both the top and bottom halves of the kaiser roll. Place the double-decker mushroom on the bottom half, then place the prosciutto slice on top. Finally, top with basil leaves and the other half of the roll. Press lightly so some of the juices from the mushrooms will run into the bottom half of the roll. Serve immediately. Yum!