Burger Bonanza! Portobello-Swiss Burgers
This recipe came out of a serious love of mushroom-Swiss cheeseburgers and a serious hate for burger joints that do nothing more than slap a portobello mushroom cap on a grill for vegetarians. It was actually inspired by a neighborhood restaurant that does way more than toast a mushroom cap and call it a day. The first three or four times I had the mushroom burger at The Argonaut on H. St., it was an awesome chunky patty of mushrooms and a few other vegetables held together with breadcrumbs, egg and a slice of cheese on top — far superior to any lame portobello “burger” I’d seen or tasted elsewhere.
But the last couple of times I’ve been there, something has seemed off about the mushroom burger. It was a little vinegary and with way more breadcrumbs than usual. Veggies other than mushrooms were more noticeable than before, especially chunks of celery, which made for a weird textural element. I found myself absently thinking about hitting the nearby Rally’s to make up for it (I am not too proud to admit my serious weakness for their mushroom-Swiss burger; no one’s perfect).
There are plenty of other tasty options at The Argonaut for future visits, but I didn’t want to go without an awesome mushroom burger permanently if they’ve changed their recipe. So I set about inventing my own chunky mushroom patty, with a bit of a nod to those sloppy, cheesy drive-thru burgers to boot.
Portobello-Swiss Mushroom Burgers
1/2 ounce dried porcini mushrooms
8 ounces baby Portobello mushrooms (sometimes seen as crimini), washed, trimmed and quartered
1 shallot, minced
1 teaspoon fresh thyme, chopped
½ teaspoon cumin and
½ teaspoon celery salt
¼ cup panko breadcrumbs
1 large egg
1/2 cup grated Swiss cheese, divided (I like emmenthaler for this)
2 multigrain buns
lettuce, tomato and other fixin’s as desired
Soak porcinis in 1 cup boiling water until softened, about 20 minutes. Drain, reserving liquid, and chop.
In a large sauté pan over medium heat, add 1 Tablespoon olive oil and cook shallot until softened. Stir in celery salt and cumin and cook until fragrant, about 1 minute. Add porcinis and cook off some of their remaining liquid, 2 to 3 minutes. Add Portobello mushrooms and thyme, stir, sprinkle with a pinch of salt and cover, cook for 5 minutes.
Add ½ cup reserved porcini liquid and simmer, uncovered, until liquid has evaporated, about another 5 minutes. Remove from heat and allow to cool.
Scoop 1/4 cup of the mushroom mixture into the food processor and pulse until finely chopped, 6-8 pulses.
Stir chopped mushroom mixture, 1/4 cup shredded cheese, breadcrumbs and egg into the cooled cooked mushroom mixture until thoroughly combined. Gently form into 1-inch-thick patty and refrigerate until ready to cook (or cook right away).
Heat 1 Tablespoon olive oil in a large skillet over medium heat. Carefully lay patties in skillet and cook until slightly browned on both sides, about 5 minutes on each side, turning once. After turning, top each patty with ¼ cup grated cheese (cover the pan in the last minute or two of cooking to facilitate cheese melting).
Serve on toasted buns with your preferred fixin’s.