Grilled Balsamic- Soy Portabella Mushrooms - cooking recipe

Ingredients

for the mushrooms
3 -4 large portabella mushrooms
1/4 cup olive oil
2 tablespoons balsamic vinegar
2 tablespoons soy sauce
3 garlic cloves, minced
1/2 teaspoon red pepper flakes
1/2 teaspoon dark sesame oil
in addition
1 -2 large vidalia onions or 1 -2 large walla walla onion
olive oil
salt
pepper
3 -4 split kaiser rolls or 3 -4 sandwich buns
3 -4 slices provolone cheese
garlic aioli (optional) or mayonnaise (optional)

Preparation

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