Created by Sue on April 18, 2013
Step 1: Cut stem level to mushroom and clean mushrooms.
Step 2: Mix together olive oil, balsamic, soy, garlic, red pepper and sesame oil in a large ziplock bag or shallow marinating dish.
Step 3: Place mushrooms in bag with marinade and coat thoroughly; allow to sit for 1-3 hours, turning occasionally.
Step 4: Slice onions about 1/4-inch thick and set aside.
Step 5: Prepare grill, remembering to oil grate.
Step 6: Place mushrooms on grill (using extra marinade for a baste), and onion slices on mesh grate on grill.
Step 7: Drizzle onions with a little bit of olive oil and season with salt and pepper.
Step 8: Cook, basting mushrooms occasionally, and turning once, about 10 minutes or until tender in center.
Step 9: Do not burn onions or mushrooms (if they start cooking too fast, move them further from the hottest coals or heat source).
Step 10: Serve mushrooms with grilled onions on a kaiser roll, if desired, along with aioli or mayo and provolone cheese.
Step 11: You may microwave cheese on the mushroom for 45 seconds or so if you like it melted.