1.Cut mozzarella into 8 even slices. Cut chicken fillets in half horizontally. Top each chicken piece with a slice of cheese, a slice of prosciutto and 2 sage leaves, securing sage to prosciutto with a toothpicks.
2.Cook potatoes in a saucepan of boiling salted water for 4 minutes to par-boil. Drain.
3.Heat half the butter and half the oil in a large frying pan. Cook extra sage and potato for 2 minutes or until golden. Season; transfer to a bowl to keep warm.
4.Heat remaining oil in same pan over medium heat; cook chicken, sage-side down, in two batches, for 3 minutes each side or until cooked through. Remove from pan; cover to keep warm.
5.Add remaining butter, wine and stock to same pan, bring to the boil; reduce heat, simmer, stirring, for 5 minutes or until liquid reduces slightly. Season.
6.Serve chicken with sauce and potato.
The word saltimbocca is Italian for ‘jumps in the mouth’. The cheese will make the prosciutto stick to the chicken. Remove the toothpicks before serving. This dish goes just as well with a green salad for lunch, as it does with steamed or roasted vegetables for dinner.