For the rice, peel and finely dice the onion. Heat butter in a pot. Sauté the onion in it until transparent. Fry the rice briefly. Add 500 ml water, bring to the boil and stir in the stock. Cover and simmer for about 10 minutes.
For the Saltimbocca, wash the parsley and remove the leaves. Pat the steaks dry and season with salt and pepper. Cover with ham and parsley. Fold the steaks and fix them with wooden skewers.
Stir the unfrozen vegetables into the rice. Cover and cook for another 10 minutes. Heat the oil in a large pan. Fry the Saltimbocca for about 3 minutes on each side. Remove from the pan. Deglaze the frying pan with 5 tablespoons of water. Serve everything.