Boil, steam or microwave spinach until just wilted, rinse in cold water; drain, pat dry. Place quarter of the spinach slightly overlapping to form a rectangle the same length as a piece of veal. Spread quarter of the combined mustards, rind and dill onto a piece of veal, place veal onto spinach, roll up like a Swiss roll.

Place quarter of the prosciutto on board, slightly overlapping in 2 rows to form a rectangle. Place rolled veal onto prosciutto, roll up like a Swiss roll. Repeat process with remaining veal, mustard mixture, spinach and prosciutto.

Heat oil in baking dish, add rolls, cook, turning occasionally, until prosciutto is lightly browned. Bake, uncovered, in very hot oven about 15 minutes or until veal is cooked to your liking. Remove rolls from baking dish; keep warm.

Place baking dish over heat, add garlic and sherry, boil 2 minutes. Add extra mustard, stock and blended cornflour and water; stir over heat until sauce boils and thickens. Strain sauce, stir in extra dill.

Slice veal thickly, serve with sauce.