Skillet Burgers with Shallot-Herb Butter

1 large shallot, finely chopped (3 T.)

3 T. butter, softened

2 T. chopped Italian parsley

1/2 tsp. snipped fresh thyme

1/2 tsp. lemon zest

1 1/2 lb. 80% to 85% lean ground beef

1/2 tsp. salt

1/4 tsp. black pepper

8 oz. shiitake mushrooms, stemmed and sliced

1 T. olive oil

4 slices Swiss cheese

8 slices small firm square bread (such as English muffin toasting bread), toasted

 

In a small bowl stir together shallot, butter, parsley, thyme, and lemon zest until well combined. Set aside. Shape beef into four square patties about 1/2 inch larger than the bread. Season with salt and pepper.  Heat an extra-large heavy skillet over medium-high heat. Add 1 T. of the butter mixture to pan. When melted, add mushrooms. Cook and stir 3 minutes or just until tender. Transfer mushrooms to a medium bowl.  Add oil to skillet. When hot but not smoking, add patties to skillet. Cook 3 minutes or until browned and slightly charred. Turn and cook 3 minutes more or until done (i6o°F). Top patties with mushrooms, then cheese. Cover and cook 1 minute or until cheese is melted.  Meanwhile, spread remaining seasoned butter on four slices of toasted bread. Top with burgers and remaining bread.