Chicken Fajita Tostadas

It's been awhile since I have made this, but was looking through my recipes and I think I might have to make it soon!! It's really tasty!

Ingredients
2 med. onions, thinly sliced
2 bell peppers (ribs and seeds removed), thinly sliced
1 box (10 oz) frozen corn
1 cup prepared fresh salsa
2 tbsp olive oil
coarse salt and ground pepper
2 cups shredded cooked chicken breast
4 corn tortillas (6 inch)
1/2 cup shredded sharp cheddar

Preheat oven to 450. Line a rimmed baking sheet with foil. On foil, combine onions, peppers, corn, 1/4 cup salsa, and 1 tbsp oil; season with salt and pepper. Roast, tossing occasionally, til veggies are tender and lightly browned, about 15-20 minutes. Add chicken; stir to combine, and continue to roast til warmed through, about 5 minutes. Transfer to a serving bowl, discarding foil. Arrange tortillas on sheet.Brush with oil and top with cheese. Bake til edges are golden and cheese is melted, 5-8 minutes. Dividing evenly, top tortillas with chicken-veg mix and remaining 3/4 cup salsa.