Pre-heat oven according to the directions on the packaging of the pie shell you are using.
In a small bowl, combine the spices for your fajita seasoning. Blend well, and set aside.
In a large bowl, add the onions, bell pepper, and vegan "chicken". Add 1 TBSP olive oil and 2 tsp of the fajita seasoning; toss until everything is evenly coated. Set aside.
Brush the pie shell with 1 TBSP olive oil. Then, evenly spread 1/2 cup of the salsa over the pie shell. Once the salsa has evenly spread out, transfer the onion, pepper, and "chicken" mixture over the pizza, distributing it evenly over the shell. Finally, evenly scatter the cheese over the pizza.
Bake in the oven for 10-12 minutes, or until the crust starts to turn golden brown and the cheese is nice and melty.
Top with freshly chopped parsley or cilantro, if desired.