Ingredients
10 ounces button mushrooms, chopped (2 1/2 cups)
Kosher salt (we use Diamond Crystal) and freshly ground pepper
5 tablespoons extra-virgin olive oil, plus more for brushing
2 teaspoons minced garlic (from 2 cloves)
1 pound ground turkey, preferably dark meat
3 cups shredded romaine lettuce (from 1 head)
1 tablespoon chopped fresh dill, plus sprigs for serving
1 tablespoon fresh lemon juice
4 slices rye bread
Dijon mustard, for brushing and serving
4 ounces Havarti, sliced
Preparation
Heat a skillet over medium-high. Add mushrooms; season with salt and pepper. Cook, stirring, until tender, 5 minutes. Add 1 tablespoon oil and garlic; cook 1 minute. Let cool 10 minutes; transfer to a bowl and stir in turkey, 1 teaspoon salt, and 1/4 teaspoon pepper. Shape into four 1/2-inch-thick patties; refrigerate 20 minutes. Toss lettuce with dill, lemon juice, and 2 tablespoons oil; season.
Brush bread slices on one side with oil and on other with mustard. Heat cleaned skillet over medium-high; swirl in remaining oil. Add burgers; cook, flipping once, about 3 minutes a side. Transfer to a plate; reduce heat to low. Add bread, oil-side down; top with cheese and burgers. Cover; cook until cheese melts, 3 minutes. Serve with salad, dill sprigs, and more mustard.
