After I posted the request to the list for this type of recipe, I got a call from my mother saying she'd tracked the original one from my childhood down. (I'm a happy camper now)...so here it is.

(You can have as many potatoes and peas as you like....this is just an amount to get you started). Boil potatoes and peas separately, until tender. Combine peas with white sauce and pour over potatoes.

White Sauce: This will make a thin sauce. For a medium-thickness, change butter to 1 1/2 T and 1 T corn starch. For thick sauce, change butter to 2 T and corn starch to 2 1/2 T. Keep the rest of the ingredients the same. Melt butter, blend in corn starch, salt, and pepper. Gradually add milk. Heat to boiling, boil for 2 minutes. Stir constantly. Yields 1 C sauce.

Recipe is from my grandmother...beyond that, I don't know.