Puree the parsley with the water. Heat the butter in a pan. Sauté the spring onions. Add the rice and sauté until translucent, stirring constantly. Pour in the wine and reduce almost completely. Bring the parsley water to the boil, season with salt. Gradually add the parsley water to the rice, stirring frequently, so that the rice is always just covered with liquid. Simmer for approx. 20 mins. until the rice is creamy and al dente.
Mix the herbs, garlic, lemon zest and salt, set aside.
Stir the spinach, cheese and butter into the risotto, season. Plate up the risotto, top with the gremolata and reserved spring onion greens.