In a small bowl, combine the cumin, chile powder, 1-1/4 tsp. salt and 3/4 tsp. pepper. Sprinkle on both sides of the pork and set aside. In a blender or food processor, purée the chicken broth, green chiles (with their liquid), jalapeños, and vinegar until smooth.
Put the flour in a pie plate and dredge the pork chops, shaking to remove any excess. Heat a 12-inch skillet over medium-high heat for 1 minute. Pour in 2 Tbs. of the oil and heat until shimmering hot, about 1 minute. Add the pork chops and cook, without moving, until they’re brown around the edges and release easily from the pan, 2 to 3 minutes. Reduce the heat to medium, flip, and cook the other side until browned, about 2 minutes more. Transfer to a large plate.
Over medium-high heat, add the remaining 1 Tbs. oil and the onion to the skillet. Sprinkle with 1/2 tsp. salt and cook, stirring occasionally, until wilted and golden, about 4 minutes. Add the green chile mixture and bring to a boil. Reduce to a simmer and cook, stirring, until the mixture thickens slightly and the onions are completely tender, 2 to 3 minutes more; add a splash of chicken broth if the mixture seems dry. Season to taste with salt and pepper.
Return the chops to the pan, nestling them into the onions. Cover and simmer gently until the pork is fairly firm to the touch with just a little give, 3 to 5 minutes. With a paring knife, make a nick in a thicker chop to make sure it’s only just a little pink.
Serve the pork chops topped with the sauce.