Mushroom-Beef Burgers

Preparation

1. Step 1

   Heat a grill to medium-high and oil the grates. (The burgers can also be cooked in a lightly greased nonstick skillet over medium-high heat until golden brown, 3 to 4 minutes per side.)

2. Step 2

   In a food processor, working in 2 batches, pulse the mushrooms, scraping down the sides and bottom, until finely chopped but not puréed. (The mushrooms should be chopped so finely they almost resemble ground meat. If cut into larger pieces, they may cause the patties to fall apart on the grill.) Transfer to a large bowl and add the beef. Mix until well blended, then form into 8 equal patties, each about 4 inches wide. Pack the patties tightly and pinch any split edges together to seal. (Since the meat mixture is half mushroom, it cannot be overworked, so you don't need to worry about density.)

3. Step 3

   Season the patties with salt and pepper, and grill, undisturbed, until lightly charred underneath, 3 to 5 minutes. (Resist the urge to prod or move the burgers during these first few minutes, as they need to cook, undisturbed, to form a crust underneath. Once they have caramelized, they'll be easy to flip, but if you attempt to do so before the patties release easily, they can fall apart.) Gently flip burgers and grill until golden and cooked to medium, 3 to 4 minutes longer, topping each with a slice of cheese during the last minute of cooking. Transfer burgers to a large platter.

4. Step 4

   Build burgers with buns, preferred toppings and condiments.