1. In a large bowl, toss together all the ingredients for the filling and set it aside.
2. Place the ingredients for the sauce in a blender or food processor and puree until smooth.
3. Warm the tortillas under a damp paper towel in the microwave for 50 seconds. To serve the tacos, set out bowls of the filling, sauce, and other toppings, if you like, along with the tortillas, and let everyone assemble their own.