Thinly slice the turkey into pieces about the size of your palm and lightly pound to even thickness. Heat the butter and olive oil until frothy, sauté the garlic, then lightly flour the turkey slices and fry them over high heat, a few at a time, two minutes per side. As they are done, dry them on a double layer of paper towels. Arrange them on a deep platter, somewhat overlapping, forming one or two layers.
For the sauce, scrape the salt from the anchovies, rinse them off quickly then dry and bone them. Rinse and dry a lemon and grate the zest. Drain the brine from the green peppercorns and coarsely grind them. Squeeze the two lemons. Heat the oil in a little pan with a few sage leaves and the crushed garlic cloves. Keep the heat at a minimum and, when the garlic has colored, discard it and add the green pepper, lemon juice and grated zest. Mix well and pour the sauce over the scaloppine. Wrap the platter in cling film and keep in a cool place (not in the refrigerator!) for several hours.
These scaloppine have a fresh, slightly piquant taste and are excellent for a summer buffet. Serve cool but not cold (refrigerator temperature would make them tough), with potato salad.