To cook the rice for the meat filling, place 1/2 cup of rice in a fine-mesh sieve and rinse under cold running water until the water runs clear. Drain well. Bring the rice, pinch of salt and 1 cup of water to boil in a small or medium saucepan over high heat. Reduce heat to medium-low, cover and simmer until rice is almost done, about 10 minutes. Allow to cool slightly.
Preheat oven to 350 degrees.
To make the meat filling, heat the oil or butter in a frying pan over medium-low heat. Add the onion and fry until soft, about 7 minutes. Place in a bowl with the beef and remaining filling ingredients. Mix well to combine.
Place cored cabbage in a large pot of boiling salted water. Cook just long enough to soften leaves, about 10 - 15 minutes. Drain in a colander and cool under cold running water. Carefully remove the leaves.
Cut the thick ribs from the larger leaves, then halve the leaves; keep the smaller leaves whole. You will need 14-16 leaves. Use extra leaves and trimmings to line a deep ovenproof pot.
To make the rolls, place a generous tablespoon of meat filling at the base of each leaf, roll one turn and tuck in sides to contain the filling. Roll firmly to the end of the leaf. Repeat for each roll.
In a saucepan over high heat, bring the stock and tomato sauce to a boil. Add the garlic, lemon juice, and salt to taste. Cook for one more minute.
Arrange the rolls in a large ovenproof pan, pouring the sauce over the top. Cover and bring to a boil. Place in the oven for about 45-50 minutes.