As much as I love a good steak or spicy chicken wings hot off the barbecue, a meal cooked outside isn't complete without some grilled vegetables. Mushrooms are particularly well-suited to the task (and make a great vegetarian main dish, too), but that doesn't mean there's no wrong way to grill them. Even though mushrooms contain a high percentage of water, they tend to dry out when cooked incorrectly. But done well, grilled mushrooms are juicy and intensely flavorful, with a meaty texture. In order to achieve all that, we have to replace the moisture that cooks off on the grill.
There are a few ways of doing this. One of the most popular is to first marinate the mushrooms for a few hours, or even overnight, in an oil-based marinade. While that's a great way to add flavor, it shouldn't be the only time you do it. Flavor-building isn't just a pre-cooking step—you can (and should!) continue to do it throughout the cooking process.
This is where basting comes in. To keep your mushrooms from drying out as they grill, add some moisture—flavorful moisture—back into the mushroom during cooking by brushing it on. Using leftover marinade is an obvious route, but my favorite way to season mushrooms is with a simple mixture of melted butter and a splash of soy sauce.
A lot of recipes also have you grill the mushrooms over high direct heat. This method is okay, but one problem is that not all mushrooms cook the same way. Mushrooms come in all shapes and sizes, and while a smaller mushroom, like a cremini, cooks well above high direct heat, a larger one, like a portobello, needs a little more time over a lower temperature zone of the grill, lest it burn before cooking through.
Before you start grilling, think about the type of mushrooms you have. Big-cap varieties—like portobellos and large shiitakes—can be grilled whole without skewering because they're easy to flip. Smaller mushrooms, such as creminis, can also be cooked whole, but they're not quite big enough to go it alone. To avoid losing them through the grate, skewer them across the cap before grilling.
If your cremini or button mushrooms are on the larger side, you can slice their caps thickly first (about half an inch thick) and skewer them, too.
These four are the most popular, but they're by no means the only types of mushrooms used for grilling. Enoki and king trumpet mushrooms also work wonderfully. The best way to grill small-stem cluster mushrooms like enokis is to first divide a single cluster into smaller clumps, then bundle those smaller clumps securely with cooking twine so they don't come apart on the grill.
Meanwhile, thick-stemmed mushrooms like king trumpets should be sliced. Again, make your slices fairly thick—about half an inch—to prevent them from falling through the grate and to give them time to cook through without drying out, while also browning well.
Once you've selected your mushrooms and prepped them as needed, it's time for seasoning. Marinating is a good option, but there are alternatives. Drizzling them with olive oil and sprinkling them with kosher salt is a quick and easy way to add flavor and moisture in advance. You'll be basting the mushrooms with butter and soy sauce later, so keep in mind that this isn't all the seasoning they're going to get.
And now comes the most important part of grilling mushrooms—actually, the most important part of grilling anything: a clean, hot, well-oiled grill. Set up your grill for indirect heat by arranging the coals on one side of the charcoal grate. Once the grill is hot and ready to go, place the mushrooms toward the middle of the grate. This is where the grill's heat will be moderate, not too high and not too low, which guarantees browning while preventing excessive dehydration.
As the mushrooms cook, baste them with the butter and soy sauce mixture every few minutes and again every time you flip them.
The cooking time will vary depending on the size and type of mushroom. Large whole mushrooms (portobellos, large shiitakes, and large button mushrooms) will take five to eight minutes on each side. Sliced and skewered large mushrooms will need four to five minutes on each side. Small skewered mushrooms (like creminis), thin-stem mushrooms (like enokis), and sliced thick-stem mushrooms (like king trumpets) should be cooked for five to seven minutes on each side.
When the mushrooms are done, transfer them to a plate and let them rest for a few minutes.
Then, when they're cool enough to handle, remove and discard the skewers and twine and cut the mushrooms into bite-size pieces.
The mushrooms will be ready to eat as-is, but for an extra layer of flavor, I like to toss them in a simple dressing of roasted sesame seeds, mirin, and soy sauce. The sesame seeds add a nice nutty crunch to the meatiness of the mushrooms.
This dish is best enjoyed at room temperature, so don't worry about serving it hot off the grill. It's the perfect side dish for a variety of grilled meats, but also perfectly delicious on its own.