When we got married in 1965 this was a regular Friday night dinner. Life sure has changed! Now our cooking club is doing a "bring back the Fifties" event. My first thought was this... straight from Betty Crocker's Dinner for Two.
Heat oven to 350. Measure reserved liquid from peas and add enough milk to measure 1/3 cup. Mix liquid and soup in ungreased 1 qt.casserole. Stir in tuna, peas, onion and 1/2 cup of crushed potato chips. Bake about 20 minutes and sprinkle remaining chips on top. Bake another 10 minutes.