Char poblano under broiler or over open flame on stovetop. Cool in covered bowl then peel, seed and chop.
Preheat oven to 350F.
Combine softened butter with garlic, onions, cilantro, oregano, 2 teaspoons lime zest and juice of 1/2 lime. Pulse to combine.
Pat turkey or chicken dry and arrange on a cooling rack set over a baking sheet to let the heat circulate around the meat as it roasts. Top skin with 4 tablespoons butter. Roast 45 minutes or to internal temp of 170F, until the skin is crisp and brown. Cover with loose foil and rest 10 minutes before carving.
Meanwhile, cover potatoes with water and bring to boil. Add salt and cook to just tender. Drain and return to hot pot, mash with cheese, 1/4 cup stock, 2 tablespoons compound butter, 1/4 cup crme fraiche, chipotle paste, salt and pepper. Cover and reserve.
Pure chopped poblano with 1/2 cup stock. Heat a skillet over medium heat with remaining compound butter. Whisk in flour, cook 1 minute, then whisk in remaining 1 1/2 cups stock. Thicken and season with Worcestershire, salt and pepper. Add poblano pure then remaining crme fraiche, about 1/4 cup.
Serve sliced turkey or chicken with potatoes, gravy and a salad of tomatoes, avocado and red onion dressed with salt, pepper and juice of remaining lime alongside garnished with cilantro.