In a large skillet, cook beef and onion over medium heat until no pink remains. Drain any fat.
Stir in condensed soup, mixed vegetables, garlic powder and pepper. Cook until heated through.
Slice each baked potato in half lengthwise. Scoop out the potato flesh into a bowl leaving ⅛" potato on the outer skin.
Stir together the potato insides with butter, seasoned salt, and milk. Mash with a potato masher (or use an electric mixer) until smooth, adding additional milk if needed. Fold in ¾ cup of cheese.
Divide beef filling evenly between potato skins. Spread mashed potatoes over top of the beef filling and sprinkle with remaining cheese. Place on a baking sheet and bake for 15-20 minutes or until heated through and cheese is melted.
Notes
Potatoes can be baked in the oven, air fryer or microwave.
Mash the potatoes while warm for the best consistency.
Line baking sheet with parchment paper or foil for easy clean up.