1. Preheat the oven to 425 degrees. Mist a warm cast iron skillet with cooking spray. Add the onion, bell peppers and jalapeno. Cook over high heat, stirring occasionally, until vegetables are lightly charred, about 3 minutes.
2. Remove pan from heat and stir in the chicken, corn, lime juice, olive oil and salt.
3. Spray one side of each tortilla with cooking spray and stack, oiled sides up. Cut into quarters and nestle each tortilla triangle, oiled side down, into a muffin cup. Bake until edges are crisp, about 7 minutes. Sprinkle with the cheddar.
4. Place a spoonful of the filling into each tortilla. Dollop with sour cream and salsa. Garnish with cilantro.