Excellent small tasting menu at Ratana https://www.ratana.it/ in Milan showcasing interpretations of Chef Battisti’s revisited traditional dishes. Generous portions for a tasting menu at a great price (especially living in the US)
I am always reluctant to name anywhere as a must visit as it sets expectations always to high but for our Milan visit Ratana and Brunello were both two of the best visits. We also wanted to visit Trippa but many restaurants are closed in Milan (or Europe in general).
One recommendation in Milan (or anywhere) is really to walk a lot a bit away from regular tourist places. We had one of the best spontaneous lunches in Milan when we explored the city somewhere without many tourists and found by accident a Pugliese sandwich shop (which seem to be unable to find again in any map). And don’t miss Gelato Giusto and Pave Granite e Gelati