Preheat oven to 375. Spray a prepared baking sheet with olive oil spray.
Slice the chicken, peppers and onions into thin strips and add to a large mixing bowl. Add 1 tablespoon of olive oil and mix to coat.
Combine the chili powder, paprika, cumin, garlic powder, coriander, salt and pepper. Mix together. Add 2 tablespoons of spice mix to the chicken and veggies. Stir to coat.
Pour the veggies onto the prepared baking sheet and spread into a single layer. Place the baking sheet into the oven and bake for 15-20 minutes, flipping halfway through.
After about 15 minutes, wrap tortillas in aluminum foil and place alongside the chicken and veggies in the oven.
While the fajitas are cooking, prepare the guacamole.
Once the chicken and veggies are cooked, set them out alongside the tortillas, guacamole, and any other desired toppings and let the assembly line begin.
Cut open the avocado and discard the pit. Cross-cut the avocado in the skin and then scoop out both halves into a bowl.
Add the remaining ingredients and mash to desired consistency.