Preheat a large grill pan or grill over medium-high heat. Rub the pork chops with 3/4 teaspoon salt and a few grinds of pepper in a large bowl. Add 1/4 cup enchilada sauce, the chile powder and 2 teaspoons olive oil. Rub all over the pork and set aside at room temperature. Toss the sliced red onion with the lime juice and a pinch of salt in a medium bowl; set aside.
Heat the remaining 5 teaspoons olive oil in a saucepan over medium heat. Add the chopped red onion and cook, stirring, until softened, 3 to 4 minutes. Add the cilantro stems and remaining 2 tablespoons enchilada sauce and cook, stirring, until mostly dry, 2 minutes. Add the beans and their liquid along with 1/2 cup water; bring to a simmer. Mash about one-third of the beans against the side of the pan with a spoon. Cook until the sauce coats the beans, 10 minutes; season with salt and pepper.
Meanwhile, lightly char the tortillas on the grill pan, about 1 minute per side. Stack and wrap in a kitchen towel to keep warm.
Lightly oil the grill pan. Grill the pork chops until marked and cooked through, about 2 minutes per side. Divide the pork chops, beans, tortillas and avocado among plates. Season the avocado with salt and pepper. Toss the cilantro leaves with the sliced red onion, then add to the plates.