A Guide to Grilling Portobello Mushrooms
Few foodies have ever heard of Kennett Square, the small town (population 6,195) in southeastern Pennsylvania that is the epicenter of fungi farming in the U.S. Here, about 1 million pounds of Agarius bisporous are harvested annually—half of the country’s supply of cultivated mushrooms.
Another thing many foodies don’t know is that white button mushrooms, brown cremini mushrooms (sometimes called “baby ‘bellas”) and portobello mushrooms are all the same—just harvested at different levels of maturity. This stratification of size and color extend the harvest time, as mushrooms can double in size in hours.
The first fungi farms were started by entrepreneurial Quakers. These practical and frugal people were disturbed by the unused space beneath the flats of carnations they were cultivating for the floral industry, and got the idea to grow mushrooms. They imported spores and mycelium from Europe, and the rest is history. Today, you’ll notice dozens of concrete bunkers built into the hillsides of Chester County, all housing mushrooms. About 60 farms are in operation in the area.
While we love often-maligned button mushrooms, we prefer their mature form, portobellos. With bowl-like caps that range in size from 3 to 6 inches and hearty, umami flavors, portobellos reach their full potential when exposed to live fire. They are meaty-tasting, and readily absorb the complex flavors of wood smoke. They lend themselves to an almost infinite number of preparations—many of them acceptable to the most strident vegetarian or vegan.
How to Prepare Portobello Mushrooms for Grilling
To prepare portobellos for grilling, wipe the caps with a damp paper towel. (Some people peel them. We don’t bother.) If desired—and especially if you are combining the mushrooms with other ingredients or intend to stuff them (see ideas below)—use the edge of a metal teaspoon to remove the stem and scrape out the black gills on the underside of the mushrooms. Slice or leave whole. Grill the mushrooms over a medium-hot fire for several minutes per side, or until they are tender and have exuded some of their juices. For sliced mushrooms, we find a grill basket to be very helpful.
How to Cook Portobello Mushrooms on the Grill
Here are some of our favorite uses and preparations:
1. Marinate the mushrooms in your favorite marinade.
Marinate the mushrooms in your favorite marinade, then drain and grill until tender over a medium-hot fire, about 4 to 5 minutes per side. Check out Steven’s book, Sauces, Rubs, and Marinades for some great options. Or mix 1 part vinegar (such as balsamic) to 3 parts olive oil, then add flavorings as desired.
2. Substitute a grilled portobello for a burger.
Top with cheese and your favorite burger accompaniments—sliced tomatoes, arugula, grilled onions, a poached or fried egg, etc.
3. Cook eggs in portobello caps.
Grill a portobello on both sides until it releases some of its liquid (one mushroom can hold as much as two tablespoons). Carefully break a large egg into the bowl of the cap. Season with salt and pepper. Cover the grill. Continue to cook the mushroom until the egg is done to your liking. Garnish with chopped fresh parsley or sliced scallions. Serve with grilled bread.
4. Mix sliced grilled portobellos with salad greens.
Toss with your favorite vinaigrette.
5. Make keto-friendly pizzas.
Grill whole portobellos over a medium-hot fire until they release most of their liquid. Remove from the grill. Spread prepared pizza or marinara sauce on the underside of the mushroom cap. Top with your favorite pizza toppings—cooked sausage or chorizo, pepperoni, etc., then finish with grated cheese and a dusting of fresh herbs. Return the mushrooms to the grill and cook until the cheese is bubbling, about 5 minutes. Serve immediately.
6. Make vegetarian fajitas with grilled portobellos.
Enfold grilled sliced portobellos, strips of grilled poblanos or bell peppers, grilled onions, and avocado wedges in flour or corn tortillas. Garnish the fajitas with grated or crumbled cheese, fresh pico de gallo or smoked salsa.
7. Add finely chopped portobellos to your ground meat for moist, juicy burgers.
Remove the gills from a portobello mushroom. Finely chop. Add to ground chicken, turkey, or lean ground beef, then make sliders or burgers according to your favorite recipe. The mushrooms will keep the burgers moist as they cook.
Grilled Portobello Mushroom Recipes