Preheat the oven to 425°F. Brush a baking sheet with oil.
Heat the oil in a large skillet set over medium-high heat. Add in the ground chicken, onion, red bell pepper, and garlic. Cook, breaking up the chicken into small pieces, until browned.
Stir in the chili powder, ground cumin, and Kosher salt. Cook until fragrant, about 1 to 2 minutes.
Stir in the Taco sauce until mixed well. Remove from the heat.
Line your tortillas up on your sheet pan. Evenly divide the shredded cheese between the tortillas. Top with the filling. Fold the tacos and gently press so they stay folded. Brush the top side of the tortilla with oil.
Bake for 12 to 15 minutes until golden and crispy. Serve with desired toppings such as hot sauce, shredded lettuce, lime wedges, and guacamole.