3 pounds bone-in beef short ribs, fat trimmed
Kosher salt and freshly ground pepper
1/4 cup canola oil
3 cups chicken stock
2 dried ancho chile peppers, stemmed and seeded
2 dried New Mexico chile peppers, stemmed and seeded
4 dried cascabel chile peppers, stemmed and seeded
1 large Spanish onion, chopped
6 cloves garlic, smashed
1 cup dry red wine
1/2 cup port
12 sprigs thyme
16 hard corn taco shells
Cilantro, queso sauce, pickled red onions and green chile relish, for topping (below)
Preheat the oven to 350 degrees F. Pat the short ribs dry and season all over with salt and pepper. Heat the canola oil in a large Dutch oven over medium-high heat. Working in batches, brown the short ribs on both sides, about 8 minutes total. Remove to a plate.
Meanwhile, combine the stock and dried chiles in a medium saucepan and bring to a simmer. Remove from the heat and let steep, 15 minutes.
Discard all but 3 tablespoons oil from the Dutch oven. Add the onion and cook, stirring, until soft, about 5 minutes; add the garlic and cook 1 minute. Pour in the red wine and port and simmer, stirring, until almost completely reduced, about 12 minutes. Add the thyme and chile-stock mixture; bring to a simmer and return the short ribs to the pot. Cover, transfer to the oven and cook until the meat is tender, about 2 hours, 30 minutes.
Remove the short ribs to a bowl; shred the meat from the bone. Strain the cooking liquid into a degreasing cup and pour off the excess fat. Pour the remaining liquid into a skillet and bring to a boil. Reduce to a simmer and cook, stirring occasionally, until thickened, 10 to 15 minutes; season with salt and pepper. Add the meat and toss to coat. Fill the taco shells with the meat; top with cilantro, queso sauce, pickled onions and chile relish.
Melt 1 tablespoon butter in a saucepan over medium-high heat. Whisk in 1 tablespoon flour; cook 1 minute. Slowly whisk in 1 1/4 cups warmed whole milk; cook, whisking, until thickened, about 5 minutes. Remove from the heat and stir in 3 cups grated monterey jack and 1/4 cup grated parmesan; season with salt and pepper. Serve warm.
Pickled Red Onions:
Bring 3/4 cup lime juice, 1/4 cup each red wine vinegar and sugar, and 1 tablespoon salt to a boil in a saucepan. Remove from the heat and let cool, 5 minutes. Toss with 1 thinly sliced red onion in a bowl; cover and chill at least 4 hours, stirring occasionally.
Green Chile Relish:
Broil 2 poblano peppers until charred on all sides; transfer to a bowl, cover and set aside, 10 minutes. Peel, seed and dice. Combine with 4 diced jarred piquillo peppers, 1 tablespoon honey, 2 tablespoons canola oil, the juice of 1 lime, 1/4 cup chopped cilantro, and salt and pepper in a bowl; let sit at least 15 minutes before serving.