In a large saucepan bring the broth and the water to a boil and in the broth simmer the broccoli florets for 3 minutes, or until they are just tender. Transfer the florets with a skimmer to a bowl and reserve them. To the simmering broth add the broccoli stems, the zest, and the lemon juice and simmer the mixture for 5 minutes. While the stems are cooking, in a large heavy saucepan cook the onion and the garlic in the oil over moderately low heat, stirring, until the onion is softened and stir in the rice, stirring until each grain is coated with the oil. Add 1/2 cup of the simmering broth, stems included, and cook the mixture over moderately high heat, stirring constantly, until the broth is absorbed. Continue adding the broth mixture, 1/2 cup at a time, stirring constantly and letting each portion be absorbed before adding the next, until the rice is tender but still al dente. (The rice should take about 20 minutes to become al dente.) Stir in the reserved broccoli florets and simmer the risotto, stirring, until the florets are heated through. Remove the pan from the heat and stir in the Parmesan and salt and pepper to taste. Serves 2. RICE 4