Sweet Corn Risotto

At Eric's request:

2 ears fresh sweet corn
3 cups chicken broth
2 cups water
1/4 cup finely chopped onion
1/4 cup olive oil
2 tsp minced garlic
2 cups Arborio rice
2/3 cup dry white wine (Pinot Grigio or similar)
1/4 cup unsalted butter (in pieces)
6 oz. Asiago cheese, finely grated
1 small tomato, finely chopped (we used grape tomatoes cut in half)
1/4 cup chives, finely chopped

Working in a shallow bowl, cut off corn kernels, then scrape each cob with a knife to extract juice. Place the cobs in a small saucepan with the water and broth. Bring broth, water, and cobs to a simmer and keep at a bare simmer. In a separate 3-quart heavy saucepan, cook onion in oil over moderate heat, stirring occasionally, until softened. Add garlic and cook, stirring, for 30 seconds. Add rice and cook, stirring constantly, 1 minute, until the grains begin to toast a little. Add the wine and simmer, stirring constantly, until mostly absorbed. Add 1 cup of the simmering broth and cook at a strong simmer, stirring constantly, until the broth is absorbed. Continue simmering and adding broth to the rice mixture, about 1/2 cup at a time, stirring constantly and letting each addition become absorbed before adding the next, until rice is creamy-looking but still al dente (it should be the consistency of thick soup, and the grains should be firm but not gritty), about 18 minutes total. There may be leftover broth. Remove the pan from heat and stir in the butter cubes and 1/2 cup of grated cheese. Gently fold in tomato, corn, and chives until the butter and cheese are melted, then season to taste with salt. I sometimes also add a few small balls of fresh mozzarella at this point. Thin with leftover broth if desired and serve sprinkled with remaining cheese.

Serves 4-6.