Seeking, Be honest w/him and tell him that you don't have it written down and it's down by rote. Suggest that he do a google search for a nice recipe. Southern Living has some great recipes out there and as well as Paula Deen.
My xh after still continues to ask for things from my home and my answer is always the same....Sears, Target, Walmart, Lowes and Home Depot carrying the items and if you purchase them now, you will have a warranty/guarantee.
You don't have to say anything other than the recipe is not written down.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.