If you want a meaty-tasting burger without the meat, one appealing solution is to grill some portobello mushrooms and stuff them in buns with complementary ingredients.
Jumbo-sized portobello mushrooms, also sometimes called portabella mushrooms, are brown — also called cremini — mushrooms that have been allowed to fully mature. As they do, the caps of mushrooms greatly widen, their gills open, and these dense mushrooms develop a rich, almost meat-like flavour.
To make a burger with those mushrooms you, of course, need to remove their stems first, creating a thick disc that will shrink a bit as it cooks and be the prefect size to fit into a bun. I bag, refrigerate and save the stems for another use, such as slicing and adding them to stir-fry or pasta dish, or filling for an omelette. They can also be used to flavour stock.
To further enhance the portobello mushrooms’ already umami-rich taste, before grilling them, I marinated them a short while in other umami-rich ingredients, such as balsamic vinegar and soy sauce, and also added spices and herbs.
After the mushrooms were grilled, I topped each one with a slice of cheese, which could be mozzarella, provolone or havarti, depending on your preference. Because the mushrooms were so flavourful, I kept the other items I added to the burgers fairly simply, and they included mayonnaise, salad greens, tomatoes and grilled onions.
That said, if did you want to jazz up my portobello mushroom cheeseburgers even more, you could also add such things as roasted peppers or sliced, pickled hot peppers, and/or replace the mayonnaise with store-bought or homemade garlic-rich aioli.
To round out the meal, you could accompany the portobello mushroom cheeseburgers with a side dish or two, such as oven-fries or corn on the cob and your favourite recipe for sweet and tangy coleslaw.
When buying portobello mushrooms, choose dry, firm, uniform-looking ones. Store them in the refrigerator until ready to cook sealed in the paper bag, or plastic container, you bought them in, ensuring they are not stacked on top of each other. If very fresh they’ll keep a few days, but the mushrooms will be at their best prepared soon after purchasing.
Portobello Mushroom Cheeseburgers
Marinated, grilled, portobello mushrooms, topped with cheese, and then set in buns, with mayonnaise, lettuce, tomatoes and onions.
Preparation time: 30 minutes
Cooking time: none to 10 minutes
Makes: four servings
2 Tbsp olive oil, plus some for brushing and the grill
2 Tbsp balsamic vinegar
2 Tbsp soy sauce
1/2 tsp dried oregano
1/2 tsp dried basil
1/2 tsp onion powder
1/2 tsp smoked or regular paprika
1/4 tsp garlic powder
1/8 tsp cayenne pepper
• salt and freshly ground black pepper, to taste
4 (about 5-inch diameter) portobello mushrooms
4 (1/4-inch or so) thick slices white or red onion
4 slices mozzarella, provolone or havarti cheese
• mayonnaise, or to taste
4 hamburger buns, split and warmed (see Note)
• baby mixed salad greens or arugula, to taste
8 thin slices ripe red tomato
Preheat a barbecue or indoor grill to medium-high heat. Combine the 2 Tbsp oil, vinegar, soy sauce, oregano, basil, onion powder, paprika, garlic powder and cayenne pepper in 13- x 9-inch or similar sized dish. Pull the stems off the mushrooms. Set the portobello mushroom caps in the dish; bag, refrigerate and save the stems for another use. Brush the oil mixture in the dish all over the portobello mushroom caps. Let mushrooms marinate at room temperature 30 minutes.
Heat your barbecue or indoor grill to medium-high. Lightly brush each slice of onion with olive oil. Set on the grill and grill two minutes per side, or until tender and lightly charred. Transfer grilled onions to a plate.
Now, lightly oil your grill and set the mushrooms on it, gill-side up. Brush mushrooms with some of the marinade in the dish and cook five minutes. Turn mushrooms over, brush with remaining marinade in the dish, and cook four or five minutes more, or until tender. Lower the heat to its lowest setting. Top each mushroom with a slice cheese and cook a minute more, or until the cheese begins to melt.
Spread bottoms buns with the mayonnaise. Top the bottom buns with salad greens (or arugula) and tomatoes. Set a mushroom on each bottom bun, top with onions, set on the top buns and serve.
Note: You can warm the buns by setting them, cut-side-down, on the grill a minute or so while the mushrooms are cooking.
Eric Akis is the author of eight cookbooks. His columns appear in the Life section Wednesday and Sunday.