Heat a skillet over medium heat. Add a tablespoon extra-virgin olive oil, then add onions and poblano pepper. Saute until onions are soft and translucent, about five minutes. Add chipotle chile powder and oregano, saute another minute more. Add enchilada sauce and salsa, stir well. Nestle chicken breasts into sauce, cover and simmer until chicken is cooked through, flipping chicken once during cooking process (about 20 minutes or so).
Meanwhile, heat another skillet over medium heat. Add a teaspoon of vegetable oil to pan and fry each tortilla lightly on each side. Cool separately on a paper towel or wire rack. (This helps prevent the tortillas from getting too soggy during cooking).
Place jalapenos on a baking sheet and toss with remaining olive oil. Broil until lightly charred and soft, about 6-8 minutes, turning once. Remove jalapenos and set oven to 350F.
Remove chicken from sauce and shred. Add 2 cups sauce and 1/2 cup shredded cheese to chicken and gently mix. Divide chicken mixture among tortillas, rolling each one tightly and place in a greased 13x9 inch baking dish. Pour remaining sauce over tortillas, taking care to spread to outer edges. Top with remaining cheese.
Bake enchiladas for 20-30 minutes or until hot and bubbling and cheese is melted and lightly browned. Remove from oven and allow to rest 5-10 minutes. Top with diced avocado, chopped cilantro, sour cream and roasted jalapenos.