Place the green onion, salt, pepper, cumin, chipotle chili powder, ancho chili powder, oregano, garlic oil, tomatoes, water and lime juice in a blender and blend until smooth. Pour it over the chicken and make sure the chicken is fully coated. Let marinate at least one hour, over night if possible.
Toss the peppers with the oil and salt.
Line 2 sheet trays with parchment paper. Place all the chicken on one sheet and the peppers on the other.
Bake at 350° for 25-30 minutes or until done. Chop up and make sure the chicken is coated in the juices.
Alternatively, grill chicken and peppers on the grill. Chicken for about 5 minutes a side and the peppers in a basket.
Serve over lettuce with tomatoes and ranch. If you're not low FODMAP then feel free to add salsa and/or guacamole.