Cover the brown rice in cold water and leave to soak for 10 minutes. Meanwhile, boil the kettle. Drain the rice, tip into a non-stick pan and add 200ml boiling water and a pinch of salt. Bring to the boil, cover and cook over a low heat for 25 minutes. Leave to cool.
For the sauce, stud the onion with the cloves and put into a pan with the Avonmore milk, bay leaves and peppercorns. Bring to the boil and set aside to infuse with the flavours.
Meanwhile, remove 12 bright green leaves from the outside of the cabbages. Use the remainder of the cabbage for another meal. Drop the leaves into a pan of boiling salted water and cook for 2 minutes. Drain and refresh under cold water. Cut out and discard the thickest part of central stalk.
Preheat the oven to Gas Mark 4, 180ºC (350ºF). Add the cooked rice to the onions with the chopped herbs, paprika, minced pork, minced beef, ½ teasp. salt and some black pepper. Mix together well with your hands. Divide the mixture into 12.
Place one portion of the stuffing into the centre of each cabbage leaf, fold in the sides and roll up. Place side-by-side, seam-side down, in a lightly buttered shallow ovenproof dish. Pour over the stock, cover the dish with foil and bake for 30 minutes.
For the sauce, strain the infused milk into a jug. Melt the butter in a pan, add the flour and cook for a few seconds. Remove from the heat and gradually stir in the milk. Return to the heat and bring to the boil, stirring. Simmer for 3-4 minutes. Remove from the heat and season to taste with nutmeg, salt and pepper. Preheat the grill to high.
Drain away any excess stock from the baking dish. Pour the sauce over the cabbage leaves and cover with the sliced cheese. Grill for 2-3 minutes until golden and bubbling. Serve.