Clean the herbs, and cut into small strips. Finely slice the white part of the leek, and simmer on a low flame with oil and a bit of water. Add the herbs, and cook for 10 minutes. Add the broth, and when it comes to a boil, stir in the rice. When the rice is cooked (approx. 40 minutes), add the minced parsley. Serve, first sprinkling grated grana cheese.