- 2 tablespoons olive oil
- 1 tablespoon unsalted butter
- 12 ounces assorted mushrooms, such as cremini, lobster, chanterelles, and stemmed shiitakes, coarsely chopped
- 1 small shallot, finely diced
- Kosher salt and freshly ground black pepper
- 1 tablespoon chopped fresh thyme leaves
- 2 tablespoons chopped fresh flat-leaf parsley
- 1 1/2 pounds ground chuck (80 percent lean) or ground turkey (90 percent lean)
- 2 tablespoons canola oil
- 4 slices sharp Cheddar
- 4 hamburger buns, split; toasted if desired
1. Heat the olive oil and melt the butter in a large saute pan over high heat until almost smoking. Add the mushrooms and cook, stirring occasionally, until soft, about 5 minutes. Add the shallot, season with salt and pepper, and cook until the mushrooms are golden brown, about 5 minutes. Stir in the thyme and parsley and transfer to a bowl.
2. Divide the meat into 4 equal portions (about 6 ounces each). Form each portion loosely into a 3/4-inch-thick burger and make a deep depression in the center with your thumb. Season both sides of each burger with salt and pepper.
3. Heat a gas grill to high. Brush the burgers with canola oil and grill until desired doneness is reached. Top each with a slice of cheese and cover during the last minute of cooking.
4. Place the burgers on the bun bottoms and top each burger with a large spoonful of the mushrooms. Cover with the bun tops and serve immediately.