Preheat oven to 400°F. Brown beef in a skillet, drain, then add onions until softened.
Stir in bacon, bread crumbs, mustard, ketchup, Worcestershire, pickles, and seasonings.
Press pie crust into a greased pie dish and crimp the edges. Spread mixture evenly into the prepared crust.
Whisk egg, milk, and 1 cup of cheese together, then pour over beef mixture.
Top with the remaining cheese.
Bake for 30 minutes, checking at 15 minutes. Tent with foil if the crust browns too quickly.
Garnish with pickles, slice, and serve warm.