I have that Prune book too. Never cooked a ton out of it but the recipe for canned sardines, gherkins and hot mustard on triscuits was a real keeper, worth the price of the book. I’ve made a ton of variations on it but the mustard and the pickles never vary
i was friendly with lots of NYC French restaurant people, used to celebrate Christmas with them every year. Nobody in that crowd would have ever served foie gras
on anything other than Pepperidge farm white bread, and I thought they were right.