Ingredients
For the patties:
1 1/2 pounds ground beef
1 egg
1/4 cup minced onion
1/4 cup breadcrumbs
1 clove garlic, crushed
1/2 teaspoon salt
1/4 teaspoon pepper
For the gravy:
1 small onion, sliced
6 ounces mushrooms, sliced
1 1/2 cups beef broth
1 package brown gravy mix
1 tablespoon ketchup (optional)
1 tablespoon Dijon mustard (optional)
2 tablespoons cornstarch
Directions
1. Mix all the patty ingredients together, then form small patties about 3/4 inch thick.
2. Make a bed of onions and mushrooms in the slow cooker.
3. In a skillet, brown the steak patties on both sides. Add to the slow cooker on top of the onions and mushrooms. (You can place the raw patties directly in the slow cooker, but we highly recommend browning them first for optimal flavor.)
4. Mix all other ingredients except the cornstarch and pour over the meat and vegetables. Cover and cook on low for 5 hours.

5. Remove patties. Turn slow cooker to high, whisk in cornstarch, and cook until it thickens.
6. Return patties to the slow cooker to coat with the sauce before serving.