I can't say just one, because I have a few. This is a memorable one that I haven't had in many decades.
One of my most memorable meals was my favorite grandmother's roast beef, from beef that they grew on their ranch. She browned it well and that gave it flavor. People think that more expensive cuts taste better. It depends. I have found that cheaper cuts, such as chuck roasts, can have more fat, marbled in the meat, which gives it flavor. A cut such as round steak, has little fat through out and doesn't have as much flavor and is not as tender.
Grandma made wonderful gravy from the pan drippings of that well browned beef. I think gravy is a food group for Czechs. Then she would make mashed potatoes, that were still memorable. Serve those potatoes with that brown gravy and omg, that could be a meal. Grandfather would have seconds of gravy over bread. That is a Czech thing as well, but often as bread dumplings.