Preheat oven to 350 degrees F (175 degrees C). Lightly grease a large baking dish.
In a medium saucepan over medium heat, melt the butter and saute the green onion until tender (about 3 to 4 minutes). Add the garlic powder, then stir in the green chiles, chopped jalepino, soup's and sour cream. Mix well. Reserve 3/4 of this sauce and set aside. To the remaining 1/4 of the sauce in the saucepan, add the shredded chicken and 2/3 cup of shredded Cheddar cheese. Stir together.
Fill each flour tortilla with the chicken mixture and roll up. Place seam side down in the prepared baking dish.
In a small bowl combine the reserved 3/4 of the sauce with the milk. Spoon this mixture over the rolled tortillas Bake in the preheated oven for 30 minutes covered, take out of oven uncover and top with the remaining shredded Monteray jack cheese. put back in and bake uncovered an additional 10 minutes or until cheese is bubbly.