We ate this a lot as kids. It is very cheap to make that is probably why. We still love this now as adults.
This recipe makes a 13X9 pan, if you want an 8X8 pan, cut everything in half.
6-8 potatoes peeled & cubed
Put the cubed potatoes in boiling water cook till they are just getting soft, ( kinda 1/2 & 1/2) do not over cook. Then put into baking pan along with
2 cans Corned Beef
2 cans Peas (drained)
Mix lightly so it isn't all clumped one thing here and another there.
Then make this white sauce in a saucepan:
2 sticks of butter
4 Tbsp flour
salt n pepper to taste
4 C milk
Cook white sauce slowly till slightly thickened
Pour over corned beef, peas & potato mixture
Cook 1/2 hour or till potato's are tender @ 350°.