Preheat oven to 350 degrees. In a large skillet, heat olive oil over medium high heat. Add the sliced onion and peppers and cook for 5-7 minutes until softened.
Spread a small amount of the salsa (about 1/3 cup) evenly over the bottom of a 9×13 inch baking dish. Warm 3-4 tortillas at a time in the microwave wrapped in a damp paper towel for 30 seconds.