In 5-quart Dutch oven or 12-inch skillet, cook ground beef, onions and garlic over medium-high heat, stirring frequently, until beef is thoroughly cooked; drain.
Reduce heat to medium. Stir in salt and pepper. Cook 5 minutes, stirring frequently. Cool 5 minutes.
Line 15x10x1-inch pan with foil. Spoon beef onto foil, breaking apart as necessary. Freeze about 1 hour, stirring once, until firm.
Divide mixture into quart-sized resealable freezer plastic bags with about 2 cups in each. Seal bags; label. Freeze up to 2 months.