Preheat Blackstone Griddle to medium-high heat. Drizzle vegetable oil then add the chicken. Sprinkle the Fajita seasoning over the top. Cook the chicken for 10 minutes or until completely cooked through.
Lay the tortillas out onto the griddle and toast for 1 minute per side. Remove from the griddle.
Top the tortillas with chicken, cilantro, diced onion, and any additional toppings.
