Pound 2 veal cutlets, 80g each, between sheets of parchment paper to ⅛in / 3mm thick. Halve each cutlet and season with ¼ teaspoon of black pepper.
Fold 4 slices of prosciutto and place one on each piece of veal. Add 4 large sage leaves, one per piece, and secure with toothpicks.
Spread 2 tablespoons of all-purpose flour on a plate. Dust only the bare underside of each cutlet, shaking off excess.
Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Fry prosciutto-side down for 90 seconds, then turn and cook for about 1 minute, until the veal reaches 145°F / 63°C. Rest on a warm plate for 3 minutes.
Pour off excess oil. Add ¼ cup of dry white wine and a pinch of salt. Scrape the pan and simmer for 20-30 seconds, until reduced by half.
Turn off the heat. Swirl in 50g of cold unsalted butter, cubed, until smooth. Remove the toothpicks and spoon the sauce over the veal.
