Remove the meat from the chicken, either discarding the bones and skin or saving them to use later for stock. Shred the meat and set aside.
Heat the butter in a saute pan or skillet and, when hot, saute the jalapeno and onion over medium heat until the onion is translucent. Add the tomatoes and saute and additional minute. Add the tomato sauce and cooked chicken, season with salt and pepper, and allow to simmer for 2 minutes to blend the flavors. Set aside.
Preheat the oven to 400 degrees. To make the enchiladas, heat the oil in a heavy skillet over medium heat. Using tongs, hold a tortilla in the hot oil just long wnough to make it pliable, about 10 seconds. Drain on paper towels and place some of the filing in the center of the tortilla. Roll it and place it in an ovenproof baking dish, seam side down. Repeat with the remaining tortillas, either filling a large baking dish or 4 individual ones.
Sprinkle the cheese over the enchiladas and place in the oven until the cheese melts. Place some salsa verde and sour cream on the tortillas, and sprinkle with paprika for color. You may also want to serve with fresh sliced avacado.
Note: The tortillas can be filled a day in advance and kept, covered with plastic wrap, in the refrigerator. Reheat them in a 250 degree oven until hot, then top with cheese and raise the oven heat.