Halloween Chicken Fajitas

Name: Halloween Chicken Fajitas
Ingredients: 1 1/4 pounds boneless, skinless chicken breasts, sliced into 1/4-inch-thick strips; 2 teaspoons chili powder; 3/4 teaspoon ground cumin; Kosher salt and freshly ground black pepper; 2 tablespoons vegetable oil; 3 orange bell peppers, thinly sliced; 2 red onions, thinly sliced; 2 cloves garlic, finely chopped; 1 jalapeno, seeded if desired and chopped; 12 blue corn tortillas; 8 ounces sharp yellow Cheddar, grated; Lime wedges, avocado slices, fresh cilantro leaves and hot sauce, for serving