How To Grill Portobellos For The Tastiest No-Meat Burgers

When it comes to meaty mushrooms, portobellos rank right up at the top, especially since they're a lot easier to come by in the supermarket than other candidates (such as chicken of the woods). They can be swapped out for meat in vegetarian recipes like mushroom pot pie, and they're sufficiently large and sturdy that they can also be grilled and served on buns as super-simple veggie burgers. In order to make sure that your meat-free barbecue is a success, though, Mushroom Council president and CEO Amy Wood says there are certain steps you'll need to take. As she told The Takeout, "Like anything worth doing, preparation is the secret ingredient to a juicy, flavorful, plant-based burger that holds its own on the grill."

It all starts with proper 'shroom selection. "Look for firm, plump caps with a dry surface and uniform color," Wood advised, noting that fresh portobellos should have an earthy smell. She prefers using mushrooms with thicker caps for grilling, pointing out that they hold up better to high-heat cooking. Along the same vein, "If you're grilling whole as a burger, pick wider caps for full bun coverage."

You don't need to wash portobello mushrooms, but wiping them with a damp paper towel will remove any surface ick. Take care not to get them too wet, though. "Avoid rinsing," Wood cautioned. "As mushrooms absorb water and you want a good sear." Once the mushrooms are clean, you can either brush them with oil and sprinkle them with seasonings or soak them in a marinade. This extra step not only adds flavor but, "helps keep them from drying out and encourages a nice sear."

In Wood's opinion, "Portobellos soak up flavor beautifully, making them ideal for bold marinades." Before you simply toss them in the marinade, "Score the tops lightly with a knife if you want them to absorb even more flavor." In terms of what marinades to use, she suggested a Korean-style barbecue sauce, a marinade made from oil and balsamic vinegar, one flavored with Mediterranean-style herbs, or something sweet and spicy (like gochujang and honey). Whatever marinade you pick, soak the mushrooms for 15 to 30 minutes. "You can also finish with a glaze or sauce after grilling for an extra punch," Wood offered. Another option is to fill the caps with cheese, sauce, seasoned breadcrumbs, or any other stuffing as they grill.

Once the mushrooms have marinated and the grill is hot, there's one more step to take. "Pat the mushrooms dry just before grilling to avoid flare-ups or excess moisture," Wood said. "Then you're ready to grill." Before you do so, make sure the grill grates are oiled so the mushrooms won't stick. Cook the mushrooms for four to five minutes per side over medium to medium-high heat (anywhere between 375 and 425 degrees Fahrenheit). Flip them over and cook the other side until they darken and release their juices. According to Wood, "You'll know the mushroom is ready when it's tender to the touch." Not too tender, though, since grilled portobellos are much better when they're a little al dente.

Wood recommends brioche or ciabatta buns for building your portobello burger, and she likes to toast them first. Her preferred toppings include coleslaw, grilled onions, lettuce, pickles, roasted red peppers, and cheeses such as provolone or smoked gouda. As for condiments, she favors garlic-flavored mayonnaise, aioli, and mustard. As she describes her perfect portobello burger: "You want a balance of savory, creamy, crisp, and a little acid ... to complement the umami of the mushroom."