Add the beef, onion, and peppers to a large skillet set over medium high heat. Cook, stirring and crumbling, until the beef's completely browned. Drain the grease.
1 lb lean ground beef, 1 small yellow onion, 2 green bell peppers
Lightly grease a 9x13" baking dish and add the potatoes, seasoning mix pouches, broth, cream, and garlic to the dish. Gently stir until evenly combined.
3 cups chicken broth, 1 - 1 1/4 cups heavy cream, 1/4 tsp garlic powder, 2 4 oz boxes au gratin potatoes
Add the beef mixture to the dish, again gently stirring until evenly incorporated. Spread out in an even layer and top with pats of butter.
3-4 tbsp butter
Tightly cover the dish with aluminum foil and bake at 425° for 30 minutes.
Uncover and bake for another 15 minutes.
Carefully remove the hot dish from the oven, and let it rest for 10-15 minutes while the sauce sets up.
Serve warm & enjoy!