Wash spinach, chard and mustard greens. Remove and toss stems and ribs. Cut leaves into ribbons, 1/2 inch wide.
Bring broth and water to a simmer in a saucepan. Turn flame to low to keep it hot.
Heat olive oil in a deep pot over medium heat. Sauté onion, garlic and parsley until onion is translucent. Increase heat to high, add the greens, and season with salt and pepper. Stir and cook for 5 mn.
Add the rice, and cook, stirring constantly, until everything is very hot. Reduce heat to medium.
Begin adding hot broth 1 cup at a time, stirring constantly and allowing the broth to be absorbed before adding another cup of hot broth. It should take about 20-25 mn for the rice to absorb all of the liquid, and become al dente. When the risotto is done, it will be creamy.
When the risotto is al dente, add the cheese and 1 ounce of butter, and stir. Taste, adjust seasonings and add more butter if the risotto doesn't seem unctuous enough.