Heat 1 tablespoon olive oil in skillet over medium heat. Add onions and poblano pepper. Cook 5 minutes, or until soft and translucent. Add chile powder and oregano, cook 1 minute. Add enchilada sauce and salsa, stir well. Add chicken, covering with sauce, and simmer about 20 minutes, or until chicken is cooked through, flipping chicken once during cooking process.
Meanwhile, heat 1 teaspoon vegetable oil in skillet over medium heat. One at a time, fry tortillas lightly on each side. Cool on a paper towel or wire rack. (This helps prevent the tortillas from getting too soggy during cooking).
Place jalapeños on a baking sheet and toss with 1 tablespoon olive oil. Broil 6-8 minutes, turning once, until lightly charred and soft. Remove jalapenos and set oven to 350°F.
Remove chicken from sauce and shred. Add 2 cups sauce and 1/2 cup shredded cheese to chicken and gently mix. Divide chicken 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 20-30 minutes, or until hot and bubbling and cheese is melted and lightly browned. Remove from oven and let cool 5-10 minutes. Top with avocado, cilantro, sour cream and roasted jalapeños.