We call for fresh shiitake mushrooms, but only because they are so much more flavorful than regular button mushrooms. Feel free to use whatever mushroom you want, buttons, cremini, morels, etc. Although this recipe calls for using a grill, you can easily pan fry them on your stovetop. I would recommend using a large cast iron pan for pan frying.
- 1 pound ground beef
- A 1-ounce package of dried mushrooms (porcini, morels or other mushrooms)
- 2 teaspoons Worcestershire sauce
- 1/2 teaspoon kosher salt (add more if you like burgers a little saltier)
- 1/2 teaspoon freshly ground black pepper
- 1/2 pound fresh shiitake mushrooms (can substitute button or cremini), sliced
- 1 large onion, sliced thin (about 2 cups)
- 2 Tbsp olive oil
- 4-6 slices of Swiss cheese
- Burger buns
1 Process the dried mushrooms in a food processor, or a clean coffee grinder (grind some raw rice to clean out coffee grinds), until ground into a powder. Remove any large mushroom pieces that didn't grind down, a few small pieces will be fine.
2 In a large bowl, use your clean hands to gently mix together the meat, salt, mushroom powder, black pepper and Worcestershire sauce. Mix just until everything is mostly combined, a minute or two. Do not overwork the meat mixture or it will become tough and meatloaf-like. Shape the meat into 3-4 patties, using about a quarter to a third of a pound per patty, creating a slight indentation at the centers of the patties (this will help keep the patties fairly flat when they cook, as the sides tend to contract more than the center).
3 Prepare your grill for high, direct heat. While the grill is heating up, heat a large sauté pan over high heat for 1 minute. Add the mushrooms and dry-sauté them until they release their water, about 2-3 minutes. Add the onions and the olive oil, toss to combine and continue to sauté over high heat 1 minute. Add salt to taste and cook until the onions soften and begin to brown. Turn off the heat and place in a bowl.
4 Grill the burgers to the desired doneness, between 5-8 minutes per side, depending on the thickness of the burgers and how hot your grill is.
5 When the burgers are almost done, lay the Swiss cheese over them and allow the cheese to melt. Paint the burger buns with a little olive oil and toast them on the griddle or grill grates. To assemble, put a burger on the bun and top with the sauteed onions and mushroom mixture.