Grant Crilly is the Executive Director and cofounder of ChefSteps. Grant is a classically trained chef and, prior to ChefSteps, he worked on the award-winning cookbook series Modernist Cuisine and cooked at various restaurants, including L’Astrance in Paris, Busaba in Mumbai, and Mistral Kitchen in Seattle.

Grant Crilly

Whether you want to eat less meat or you just freaking love mushrooms as much as I do, this portobello burger recipe delivers everything you want in a burger: a deeply seasoned and juicy “patty” with a light char and substantial bite, packed with umami and spice. My goal was to maximize flavor and texture and minimize the amount of time the mushrooms spend on the grill, which can turn the caps leathery and dry. With a few tips and tricks, it’s actually pretty simple, and you can customize the flavors however you want.The main takeaway? The best way to grill portobello mushrooms is...use the microwave.Portobellos take a long time to cook on the grill; they contain a lot of water, and you want to get that bland moisture content out of the mushrooms so they become mushroomy and delicious. Scoring the mushroom caps and sticking them in a microwave—putting the mushrooms in a bowl, wrapping it in plastic, and nuking them for about two minutes—extracts a lot of moisture (about 25% of the mushrooms’ weight) very quickly, and cooks them completely without drying them out.The microwave takes care of the texture, but I wanted the burger to be tasty, packed with umami, almost “beefy.” So once the mushrooms are cooked, I marinate them in Worcestershire sauce and Montreal steak seasoning, which makes them taste super savory and steaky. The cross-hatching on the caps also helps them hold onto more sauce and seasoning, so you have an even tastier burger. Combined with the Swiss cheese, you get a nice, synergistic mix of guanylic acid (from the portobellos), inosinic acid (from the anchovies in the Worcestershire), and glutamic acid (from the cheese), which makes the final burger super savory.The mushrooms can go on the grill immediately, but they can also hang out in their marinade for up to four hours, which gives you a lot of time to get your mise and your two-zone grill setup ready. When you’re ready to grill, the caps go on the hot side of the grill, gill-side down, for just about two minutes, which is just enough time for a little char and smoky flavor to develop, then I flip them over and move them to the middle of the grill, top with sweated, sweet onions, and Swiss, and let them hang out until the cheese is melted and the buns are warmed. Finally, I smear some of the leftover butter from sweating the onions onto the buns, add a little barbecue sauce, then slide the portobello patties in, top with lettuce, and they’re ready to serve.This recipe goes in a classic mushroom/Swiss cheese/onion direction, but you can take the technique and flavor the burger any way you like. You can marinate the cross-hatched, microwaved caps in whatever you want: soy sauce, lemon pepper, fresh herb oils, chile oil...anything is fair game.The one thing you want to pay attention to is buying the right mushrooms. When selecting your portobellos, look for ones that have caps that are still semi-closed. They’ll be thicker and more evenly textured after cooking, which will help with even grilling and produce a more substantial, “meaty” bite.

Super-Savory Grilled Portobello Mushroom Burgers