1. Trim fat from pork. In a 3 1/2- or 4-quart slow cooker combine pork shoulder, broth, onion, garlic, cumin, ground chipotle chile pepper or chili powder, and salt. Cover and cook on low-heat setting for 10 to 11 hours or on high-heat setting for 5 to 6 hours.
2. Preheat oven to 400°F. Remove pork from slow cooker, reserving cooking liquid. Using two forks, pull meat into coarse strands.*
3. In a large bowl combine pork, 1/2 cup of the enchilada sauce, 2 tablespoons of the reserved cooking liquid, and the 1 tablespoon snipped cilantro. Set aside.
4. In a medium bowl combine the remaining enchilada sauce, 1/4 cup of the reserved cooking liquid (discard any remaining cooking liquid), and the diced green chile peppers. Spread about 1/2 cup of enchilada-green chile pepper mixture in the bottom of a 3-quart rectangular baking dish; set aside.
5. Divide pork mixture and 1 1/2 cups of the cheese among tortillas, placing meat and cheese near the edge of each tortilla. Roll up tortillas. Place filled tortillas, seam sides down, in the prepared baking dish (place tortillas close together); top with the remaining enchilada-green chile pepper mixture. Cover with foil; bake for 25 minutes. Sprinkle with the remaining 1/2 cup cheese. Bake, uncovered, about 5 minutes more or until heated through and cheese is softened and starts to brown slightly.
6. Sprinkle with additional snipped cilantro and tomato. If desired, serve with sour cream. Makes 6 servings
*Test Kitchen Tip:At this point, the meat and cooking liquid can be refrigerated overnight before assembling enchiladas. The cooking liquid will thicken. To serve, pour cooking liquid into a small saucepan; heat over low heat until boiling. Continue as directed in Steps 3 through 6.