Open-Faced Beef Stroganoff Meatball Sandwiches

Preheat oven to 350ºF.

For the meatballs:
Spray a baking sheet with nonstick cooking spray. In a large bowl, combine beef, egg, milk, breadcrumbs, Worcestershire sauce, minced onion, and salt and pepper. Roll beef mixture into 1-inch balls and place on baking sheet. Bake for about 15–20 minutes or until cooked through. Remove from oven and set aside.

To make the sandwich, spray another baking sheet with nonstick cooking spray. Place sub slices on the baking sheet and top with 3 to 4 meatballs. Pour sauce over meatballs and top with provolone. Repeat the process with remaining sandwiches. Place baking sheet under broiler for a couple of minutes or until cheese is bubbly and brown. Remove from oven and serve immediately.

For the sauce:
In a large skillet, melt butter. Add onion, Worcestershire, mushroom, salt and pepper, and cook until softened, about 5 minutes. Add flour, stir, and cook for about 1 minute. Pour in stock and stir until thickened. Reduce heatt to simmer and stir in sour cream. Remove skillet from heat.

Recipe adapted from Taste of Home.