Our must have is dressing. My mother taught me how to make it about 10 years before she died and I don't think she ever made it again. It was my job. My DMIL would serve stove-top, so my DH never had anything like my home-made dressing until he met me. Now his whole family requests my dressing at Thanksgiving and Christmas. My mother was an awesome cook and I'm so thankful she showed me how to make certain dishes for which she never had a recipe. It was funny when she would shake salt or something into her palm and say "this much" and I'd scream for her not to move while I grabbed a measuring cup or spoon to see "how much" and write it down! (Of course, now I rarely consult the recipe... and the results are always better than when I do! lol)