Preheat oven to 375F. Bring a large pot of water to a boil over high heat, and fill a large mixing bowl with ice water.

Start by preparing the peppers. Slice the top off each pepper about 1″ from the stem end, then remove any seeds or ribs left inside. If any of the peppers are a little crooked, slice a little off the bottom until they stand up straight.

Cook the peppers in the boiling water for 3 minutes, then use a slotted spoon to transfer them to the ice water bath to stop the cooking process. Arrange the peppers cut side up in a baking dish, and set aside.

Next, make the filling. In a large skillet set over medium-high heat, heat the canola oil. Add the onion to the canola oil, and saute for 5-7 minutes or until soft. Stir in the rice, beans, corn, salsa, and chili powder, and continue cooking for 5 minutes or until everything is heated through.

Remove from heat and stir in the cilantro, then season to taste with hot sauce, salt and pepper. Spoon the rice mixture into the peppers, making sure not to pack too tightly.

Bake in preheated oven for 25-30 minutes or until peppers are tender. Sprinkle the tops with cheese and continue baking for 5 minutes longer, or until the cheese is melted and bubbly. Serve right away.