When ready to cook, start the Traeger grill on Smoke with the lid open until the fire is established (4 to 5 minutes).
Generously season the pork ribs on both sides with Traeger Pork and Poultry Shake, or salt and black pepper. Lay the pork directly on the grill grate and smoke, turning once, for 1-1/2 hours. Spray periodically with the beer to keep the meat moist.
Remove from the grill grate and transfer to a platter or aluminum foil pan. Cover and let rest.
Increase the temperature of the Traeger to High. Arrange the chile peppers - including the jalapenos - the onions, and the tomatillos on the grill grate. Work in batches if necessary. Roast, turning with tongs as needed, until all sides of the peppers and onions are blackened and the tomatillos are browned. Transfer to a platter or large aluminum foil pan and cover with plastic wrap.
When the chiles are cool enough to handle, peel off most of the blackened skin, then remove the stems and the seeds. Tear into broad strips. Peel the blackened skin off the onions, trim off the stem ends, and coarsely chop.
coarsely puree the chiles, tomatillos, onions, cilantro, garlic, 4 to 5 cup of the chicken broth, the cumin, and oregano, working in batches. Transfer to two Dutch ovens or other heat-proof vessels. If the chili seems dry, add additional chicken broth until the right consistency is achieved.
Reduce the temperature of the Traeger to 300. Bury the pork country-style ribs in the chili. Cover the pot(s) with lids or aluminum foil. Braise the chili for 1-1/2 to 2 hours.
Carefully transfer the chili to a heatproof surface. With tongs, remove the pork country-style ribs to a cutting board. Remove the bones, if any, and chop the pork into bite-size pieces. Return the meat to the chili and stir to distribute.
Taste for seasoning, adding more cumin or salt if needed. Serve in bowls with sour cream, if desired, and sprigs of cilantro.