These are more filling than you might anticipate, but if you’re feeding a very hungry crowd, serve with a bean salad, rice, or lentils.
- 6 portobello mushroom caps (about 1 1/2 lbs.)
- 1/4 C balsamic vinegar
- 2 T tamari (or soy sauce)
- 3 T + 1 t olive oil
- 2 T minced fresh rosemary (substitute 2 t dried, in a pinch)
- 1 T grill seasoning
- 2 T minced red onion
- 2 smashed garlic cloves
- 2 pints grape tomatoes (about 2 lbs. or 6 cups)
- 6 C baby or regular spinach (about 6 handfuls)
- 4 oz. grated cheese or 6 to 12 thin slices (fontina, Swiss, or provolone work great)
- Combine the vinegar, soy sauce, 3 T olive oil, rosemary, grill seasoning, onion, and garlic in a pourable measuring cup or bowl. Allow to stand while you wipe the dirt off the mushrooms and place them in a large baking dish. Slowly pour marinade over the mushrooms, getting some on each cap. Let marinate at room temperature for 30 to 90 minutes, occasionally spooning or brushing more marinade over mushrooms.
- While the mushrooms marinate, wash and halve the baby tomatoes. If you’re really short on time, it won’t hurt to leave them whole (they’ll just require a bit more cutting to eat). Just before the mushrooms are done marinating, heat 1 t oil over medium heat in a skillet, then add tomatoes and saute until just softened, no more than 2 minutes. Add the spinach and cook until wilted, then immediately remove from heat and drain off excess liquid (I drained in a colander then returned to the pan). Sprinkle with salt and pepper.
- Heat grill or grill pan to medium. If using a grill pan, also preheat oven broiler. Remove mushrooms from marinade, brushing off seasonings, and place gill side down on grill pan for 5 minutes. They may stick a little but should release easily with a rubber spatula. Turn over, carefully distribute vegetable filling evenly amongst mushroom caps using a tongs, and top with cheese. Grill for another 5 minutes, closing grill lid to melt the cheese. If using a grill pan, heat mushrooms under broiler for two minutes (on a baking sheet) to melt and brown the cheese.
- Serve mushrooms with more balsamic vinegar and pepper.
Gluten-free and meatless.
Oven-only method: Instead of heating the grill and the oven, heat only the oven to 450 degrees (not to broil) and position the rack in the top third of the oven. Line a baking sheet with foil and place the mushrooms gill side down after wiping off the excess marinade. If you have a wire race or broiler pan, use that so excess moisture drips off the mushrooms. Cook for 5 minutes. Remove from oven, carefully turn to face up, then fill with the spinach and tomato mixture and top with cheese. Return to oven for another 5 to 8 minutes, or until cheese is melted and beginning to brown.
The easiest way to handle the filled mushrooms is with a spatula underneath and a tongs to hold the sides steady.
Portobello caps are often less expensive when purchased by the pound than when purchased pre-packaged.
- Category: Entree
- Cuisine: Vegetarian