Vanna Corbellarti Camerlenghi’s Mantuan frittata is richer than the usual Italian flat omelet because she adds a few drops of milk, a handful of bread crumbs, and an impressive amount of Parmesan cheese. If you can possibly find them, use small white spring onions because their sweetness is so enticing. This frittata makes a wonderful centerpiece for brunch or Sunday supper, but you can also cut it into small wedges and serve it as an antipasto or take it along on a picnic.
