Season both sides of the ribs with the ancho chile powder. Wrap tightly in plastic wrap and refrigerate at least 6 hours or overnight.
Preheat the oven to 350 degrees F.
Place a roasting pan over 2 burners on the stove. Add oil and sear ribs on all sides. Add the soy sauce, ancho chile, onion, garlic, Worcestershire sauce, brown sugar, kosher salt, and water to the roasting pan, and bring to a simmer over medium-high heat. Adjust the seasoning, to taste, and tightly cover, and transfer to the oven. Cook until the ribs are tender and fall from the bones, about 3 to 3 1/2 hours.
Remove from the oven and serve on top of the cheddar polenta, with the cooking liquid spooned over the top.
Yield: 8 appetizer servings