Preheat the oven to 425 degrees F. On a baking sheet, toss together the chicken, olive oil, chili powder, smoked paprika, oregano, garlic powder, and a pinch each of salt and pepper. Arrange in a single layer on one side of the pan. In the middle of the pan, toss the bell peppers, onions, 1 tablespoon olive oil, and a pinch of salt and pepper together. To the remaining 1/3 of the pan, add the tomatillos, jalapeño, and green onions. Transfer to the oven and roast 20-25 minutes or until the chicken is cooked and the tomatillos lightly charred. Set the chicken, peppers, and onions aside. To make the salsa: de-seed the jalapeño, if desired. To a blender, add the roasted tomatillos, jalapeño, green onions, lime juice, and cilantro. Pulse until smooth. Stir in the pineapple and a pinch of salt. Stuff the chicken, peppers, and onions into the warmed tortillas, and top with the salsa, avocado, and cheese. Enjoy!