1teaspoonblack pepper, or favorite burger seasoning or your choice
4tablespoonsbutter, or mayo
TO MAKE THE FILLING, cut mushrooms into small pieces.
Heat a large skillet over medium high heat.
Once oil is hot, add chopped mushrooms and Worcestershire sauce. Cook until mushrooms nicely browned, 8-10 minutes, stirring occasionally. Remove from heat and cool.
Mix cooled mushroom with feta cheese.
TO SHAPE THE BURGERS, divide beef into 8 equal parts, 3oz each, and then flatten each one into thin patties, about ¼-inch thick.
Place the mushroom and feta filling in the middle of 4 patties. Then top them with the other 4 smaller patties and seal the edges. (To make this process much easier, use this burger press. Read the directions inNOTES 1.)
Season the burgers with salt and pepper, or your favorite burger seasoning.
Heat the grill to medium heat for at least 5 minutes.
TO COOK THE BURGERS, grill the burgers over medium heat until cooked through, about 4 minutes per side. (Aim for 160°F internal temperature.)
Meanwhile, butter the buns and toast lightly over low heat until golden brown and crispy.
Serve the burgers on prepared toasted buns with other desired toppings and garnishes.
Note 1: If you’re using a burger press, like this one, divide the meat into 4 x 4oz and 4 x 2oz balls. Then place 4oz meat into the bottom of the press, flatten it using the press for stuffed burger, making a well in the middle. Fill with quarter of the filling and then place 2oz meat on top and push with flat press.