Cut the meat into portions, season with salt and pepper and place in a non-stick pan.
Grate the onion and put it in the pan along with extra virgin olive oil, grated garlic, wine and tomato juice.
Add 2 cups of water and put it in the oven for 1 ½ hours at 190°C. In a preheated oven.
After about 1 hour and 30 minutes, when the meat is tender, remove the lamb from the oven, place it in a pot and add 12 cups of water.
When the water boils, add the orzo and stir it lightly, quite often for the first 3 minutes.
After about 10 minutes the food is ready. Add the grated gruyere and mix.