Bring broth to a simmer in a 2-quart saucepan (do not boil). Keep warm over low heat.
Heat a Dutch oven over medium heat. Add olive oil and butter; cook until butter melts. Add onion; cook 2 minutes or until golden, stirring occasionally. Add rice; cook 1 minute, stirring constantly. Stir in wine; cook 1 to 2 minutes or until wine evaporates, stirring constantly. Add broth, 1 cup at a time, stirring constantly until each portion of broth is absorbed before adding the next (about 12 minutes total). Remove from heat.
Add corn, next 3 ingredients (through salt), and 1/3 cup cheese, stirring gently until cheese melts. Sprinkle with remaining cheese. Serve immediately.
Tip: If you've never made risotto, there are a few tricks. Make sure your broth is warm. Also, you always want to keep a thin veil of liquid on the rice. When it starts to evaporate, you know it's time to add more. And keep stirring! It may seem like forever, but risotto only takes 12 to 15 minutes to cook once you've added the rice to the pan. Toward the end of cooking, make sure to keep tasting it. You want to pull it off the heat while it's still a bit al dente.