Sort of tastes like sherpard's pie. Cook the potatoes in the microwave for ultimate ease. Can be doubled or cut down easily. Freezes well and great for OAMC. Time doesn't include initial baking time for potatoes.
Brown beef and onions in skillet seasoning with salt and pepper once it begins to brown, drain. Scoop centers from potatoes, mash. Add mayonnaise, milk and cheddar cheese. Mix beef with mashed potatoes mixture. Add garlic salt and adjust seasonings. Spoon into shells of baked potatoes.
Bake 350 degrees for 30 minutes (or can microwave). Top with butter, extra cheese and sour cream. Freezes well.