Cut the pork ribs into large bite-size chunks - about 1-inch cubes. Spread them out over a couple of paper towels and pat dry.

Add the oil to a large stockpot or dutch oven and set it over medium high heat. When the oil is very hot and shimmering, add enough pork to cover the bottom of the pan without any of the pieces overlapping. Sprinkle generously with salt and pepper.

Let cook, undisturbed, for 2 or 3 minutes, until brown on the bottom. Use metal tongs to flip the pieces over and allow them to brown on the other side. Remove the pork from the pan to a plate and repeat with the remaining pieces of pork.

Turn the heat under the pan down to medium and add the chopped onion. Cook, stirring frequently, until the onion is soft and translucent, about 3-4 minutes.

Add the garlic, jalapeño, chili powder, cumin, oregano, and 2 tsp salt. Cook, stirring constantly, for 2 minutes longer.

Add the butter to the pan and stir it around until it's melted. Sprinkle in the flour and cook, stirring constantly, for 1 minute.

Pour in the broth, scrapping at the bottom of the pan to loosen any little brown bits of flavor that might be stuck there.

Add the enchilada sauce, diced tomatoes, green chiles, chipotle peppers, Worcestershire, sugar and the pork. Turn the heat to high and bring to a boil, then lower the heat and cover partially so that the lid is set slightly askew to allow steam to escape.

Let the green chili simmer over low heat for 2 hours, lifting the lid and stirring every once in a while.

Remove the lid and let the chili simmer for another 30-60 minutes, stirring often, until it's thickened slightly.

Turn off the heat and stir in 2 tablespoons lime juice. Taste and add as much more lime juice and salt as you like.

Serve sprinkled with fresh cilantro if desired.