Shroomy Mushroom Burger
I love grilled portabellas that have been marinated in a soy vinegar marinade and wanted to make a burger that featured this magnificent mushroom.
4 1/2 tablespoons soy sauce, divided
6 tablespoons seasoned rice vinegar
1 tablespoon garlic, minced
1 ½ teaspoons fresh ginger, grated or minced
6 portabella mushrooms
2 ounces dried wild mushrooms, divided
2 pounds ground beef chuck
1 ½ tablespoons soy sauce
2 ½ teaspoon black pepper, divided
1 teaspoon kosher salt
3 tablespoons vegetable oil for the grill grate
12 leaves of fresh spinach
24 slices of pickled ginger
1/3 cup mayonnaise
6 Sesame seed buns
For the portabella mushrooms:
In a small bowl, combine 3 tablespoons of the soy sauce, rice vinegar, garlic, and ginger. Stir to combine. Remove the stem and gills from the underside of each portabella mushroom . Place the mushrooms in a large zip-top plastic bag and pour the marinade over them. Shake to evenly distribute the marinade. Set aside while preparing the rest of the burger, but give the bag a shake every now and then to redistribute the marinade.
For the patties:
Grind the dried mushrooms to a fine powder in an electric spice grinder, coffee grinder, or food processor. Set aside.
Crumble the beef into a large mixing bowl, add the remaining 1 ½ tablespoons of soy sauce, 1 ½ teaspoons black pepper, and 2 tablespoons of the mushroom powder. Gently blend the seasonings into the beef, mixing as minimally as possible so the meat doesn’t become dense and compact. Form the beef into 6 equal sized patties pressed out to equal the diameter of the buns.
In a small bowl, combine 2 tablespoons of mushroom powder, 1 teaspoon of salt and the remaining teaspoon of black pepper. Dust each side of the patties with ½ teaspoon of the seasoned powdered mushroom mix and pat it into the burger so that it sticks. Set the patties on a sheet pan and refrigerate until ready to grill.
Grilling the portabella mushrooms:
Preheat a gas grill on high. Once hot, turn the heat down to medium low. Rub the grill grate with an oiled paper towel to prevent the mushrooms from sticking to the grill. Place the mushrooms on the grill, stem side up and let cook 4-5 minutes. Adjust the heat as necessary to prevent the exterior of the mushroom from getting too charred before the center is cooked. Flip the mushrooms once the first side has good grill marks and a roasted appearance. Continue to cook until the second side is nicely grilled another 4-6 minutes. Set the mushrooms aside until the burgers are assembled.
Increase the grill heat to high and give it a few minutes to heat up. Once hot, turn the heat down to medium-high. Rub the grate with oil once again and place the burgers on the grill. Let them cook on the first side for 3 minutes. Flip the patties and continue to cook on the second side for and additional 3-4 minutes, or until they reach your desired level of doneness (the USDA recommends cooking ground beef to 160 degrees F). Watch them carefully to avoid over cooking them if you prefer a slightly pink burger.
Once the burgers are flipped, if there is room, place the buns cut side down on the grill to toast them. If there isn’t room, toast them briefly as soon as the burgers are removed from the grill. Once the buns have a slightly toasted appearance and are warm to touch, remove them from the grill.
Assemble the burger:
Place the bottom half of the buns on plates and top with a burger. Lay 4 slices of pickled ginger on each patty and then place a grilled portabella mushroom on each burger. Add 2 large spinach leaves to each burger. Spread each top bun with a shy tablespoon of mayonnaise and place on the burger. Served immediately & enjoy!