Cut off the onion tops almost one-third of the way down, then remove the centre from each onion.

Bring the water and a little salt to the boil in a large saucepan, add the onion outsides and boil them for 20 minutes.

Wash and drain the rice, pat dry and cook for a few minutes in the butter. Add the stock and simmer for 20 minutes.

Chop the onion lids and in-sides. Peel the tomatoes and cut them into strips. Dice the ham.

Heat the oil in a frying pan, add and fry the chopped onion until transparent. Add the ham, tomato and rice and season with the parsley, salt, pepper and paprika.

Stuff the onions with the mixture and arrange them in a buttered ovenproof dish. Stir the cheese with the milk and soured cream. Season the sauce with paprika and herbs and pour it over the onions.

Bake in a hot oven (220°C, 425°F, gas 7) for 15 minutes.