Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.

Cook the meat:
In a large skillet, brown ground beef or sausage with chopped onion. Drain excess fat.

Par-cook potatoes:
Boil diced potatoes for 8–10 minutes until just tender (or microwave covered with a bit of water for ~5 minutes). Drain.

Mix the base:
In a large bowl, stir together the cream of mushroom soup, sour cream, milk, garlic powder, salt, pepper, and thyme.

Assemble the casserole:
In the baking dish, layer:

Cooked meat/onion mixture

Par-cooked potatoes

Green beans and corn

Pour creamy base over all and stir gently to combine.

Top it off:
Sprinkle with shredded cheese. Add crushed crackers or fried onions on top if desired.

Bake:
Cover with foil and bake for 30 minutes.
Remove foil and bake uncovered for another 10–15 minutes until bubbly and golden on top.

Let rest 5 minutes before serving. Then watch it disappear.

🍞 Serving Ideas:
Serve with homemade dinner rolls, buttered egg noodles, or a simple apple slaw.

Add a slice of shoofly pie for an authentic Amish finish.