Saute the rice in a tablespoon of olive oil, stirring continuously, for 3 to 4 minutes. The rice will begin to smell nutty, somewhat reminiscent of popcorn. Add the bay leaves, salt, tomato paste, and water and stir until the tomato paste is dissolved. Cover and cook until tender.
Immerse the cored head of cabbage in boiling water. After several minutes, as each leaf begins to separate from the head, gently but nimbly pull it completely off the cabbage and set aside to cool. Continue until there are 12 good leaves to stuff.
NOTE: If cabbage leaves are especially white and seem tough arrange in layers on baking sheet after steaming. Cover, Freeze overnight, and thaw completely before using - the leaves will be easy to roll after freezing and thawing.
Combine the nuts, mint, and parsley in a mixing bowl. When the rice is ready, remove the bay leaves and add the rice to the nuts. Mix in 2 to 3 tablespoons of olive oil, the garlic, and half the lemon juice.
Make a thin sauce by crushing the tomatoes in their juice and then mixing in the salt and pepper, lemon juice, and the remaining olive oil. Thin the sauce with water if necessary. Ladle some of the sauce into a large skillet or soup pot.
Put 1/3 to 1/2 cup of the rice nut filling on the thick end of each cabbage leaf. Fold the sides over the mixture and then roll up toward the thin edge of the leaf. Arrange the cabbage rolls on top of the sauce, seam side down. Pour the rest of the sauce over the rolls, cover, and simmer for 30 to 45 minutes. Test the cabbage for tenderness by piercing with a fork.
Top with a dollop of yogurt and more chopped parsley if desired. Serves 6.