Start by preheating your oven to 425°F and lightly greasing a large sheet pan. Slice your chicken and vegetables into uniform strips. Placing the sliced vegetables on the pan first with the chicken on top helps everything cook evenly.
In a small bowl, mix together all the ingredients for the fajita seasoning. Sprinkle the seasoning generously over the chicken and vegetables, then add the minced garlic and drizzle with oil. Use your hands or tongs to toss everything together until it's well-coated.
Spread the chicken and vegetable mixture in an even layer across the sheet pan. Bake for 15-20 minutes, or until the chicken is cooked through and the vegetables are tender-crisp. During the last 5 minutes of cooking, wrap your tortillas in foil and place them in the oven to warm up. Once everything is out of the oven, squeeze fresh lime juice over the top and sprinkle with cilantro before serving.