Grilling season is upon us! But did you also know that today is National Hamburger Day? I thought I’d observe this hugely important holiday—as well as Official Summer Kickoff Weekend—by putting up a recipe for a veggie burger that works on the grill.
While developing the recipes for the book I was disappointed to conclude that homemade veggie burgers are not ideal barbecue food. When making a traditional veggie burger—one held together by some kind of binder, in most cases egg and bread crumbs—you want to be able to use as little starch (breadcrumbs) as possible to avoid washing out the other flavors. I get away with this by making burgers that only loosely hold their shape before cooked, and then firm up when applied to heat on the stove top and in the oven. However, if you try to cook the same burgers on a grill, they will likely seep through the grates.
One way around this is to treat your grill as more of an oven and cook the burgers (or a smoker if you have one, which makes for a delicious veggie burger) on a double-layer of foil fashioned into a backing sheet or another flat surface. Gretchen McKay at the Pittsburgh Post-Gazette recommends chilling them completely before popping them onto the grill—a useful tip that stupidly didn’t occur to me while I was writing the recipes.
But a Portobello burger skirts the issue entirely. I know what you’re thinking: “A Portobello burger. That’s never been done before.” But bear with me. Portobello burgers seem to pop up most often as one of two veggie options (a frozen hockey-puck veggie burger being one of them) at burger joints (where, incidentally, there are 15 variations on a traditional hamburger) as a “roasted vegetable Panini.” Said sandwich consists of zucchini, canned roasted red peppers, and a Portobello mushroom that’s lavishly dressed in a gag-inducing, cloyingly sweet balsamic marinade. The cook flops the veggies on the grill for a few minutes before sandwiching them between two slices of bread that promptly disintegrate.
I knew that my Portobello burger, on the other hand, would have to be savory and earthy so that it highlights the natural flavors of the mushroom. Miso paste turned out to be the answer. For years I’ve been using miso paste in salad dressings and marinades, and here it offers a warm, multi-dimensional saltiness that makes for a Portobello mushroom burger you actually do want to eat. And ever since I served it with avocado, picked red onions, a squirt of Sriracha, and lettuce for a mock-Top Chef competition that my friends and I had going last year—at which competition I won!—I haven’t bothered serving it any other way. For your Memorial Day cook-outs, they are perfect burgers. There’s no need to serve them as a your vegan or vegetarian option—everyone is going to want to eat them.
Portobello Mushroom Burgers
Makes 4 burgers
4 portobello mushrooms
3 tablespoons olive oil
1 tablespoon rice vinegar
2 teaspoons miso paste (gluten-free if necessary)
½ teaspoon freshly ground black pepper
Trim off the stems of the mushrooms and scrape out the gills with a spoon. Place the caps in a large baking dish or mixing bowl.
In a small bowl, whisk together the oil, vinegar, miso, and pepper. Pour over the mushrooms and, using your hands, toss to ensure that all the mushrooms are evenly coated. Marinade for at least 15 minutes or up to 2 hours.
Grill method: Prepare a medium fire over a charcoal or gas grill. Grill the mushrooms over an open flame for a total of 10 to 12 minutes, beginning with the rounded top down and flipping halfway through.
Stovetop method: Heat a large sauté pan over medium-high heat. Add the mushrooms, rounded tops down, and cook for 10 to 15 minutes total, flipping them halfway through. The mushrooms should be tender in the thick center. Watch for them to release their juices, and then for most of the liquid to cook off the pan.
To serve, place a cooked mushroom over a layer of avocado slices and a squirt of Sriracha, and top with a few picked red onion slices and a handful of crunchy lettuce.