Put hamburger mixture into a casserole dish and spread out on the bottom of the dish.
Put cream of mushroom soup on top of hamburger mixture and spread out.
Add the onion and celery on top of the soup.
Next, put the diced potatoes on top to cover.
Sprinkle with salt.
Pour milk on top.
Cover and bake for 1 1/2 hours at 350 degrees.
Notes
I always eye the amount of potato I put on. So the 3-4 for large potatoes isn’t and ecxact amount. You can add more or less to your liking. Also the milk just sits on top of the hot dish, dont stir it in. When it first comes out of oven it can be a little runny, after it cools a bit it thickens up. Tastes even better the next day. ~Enjoy~