Season 2 pounds boneless beef round steak, cut into 8 thin pieces on both sides with ½ teaspoon salt and ½ teaspoon black pepper.
Place half of the sliced onions and half of the minced garlic into the bottom of a 6-8 quart slow cooker.
Top the onions with the seasoned steaks.
Sprinkle 1 packet brown gravy mix on top.
Spread the remaining sliced onion and remaining minced garlic on top.
Pour in 2 cups unsalted beef stock.
Place the lid on and cook on low for 7-8 hours or high for 5-6 hours.
During the last half hour of cooking, take out about ½ cup of the sauce and mix it with 3 Tablespoons cornstarch in a medium bowl.
Pour the mixture back into the slow cooker and stir to combine.
Place the lid on and turn up the heat to high; cook for the remaining 30 minutes or until thickened.
Serve immediately.
