In a resealable plastic bag, coat the chicken with the tea, Worcestershire, Tabasco, thyme and 1 tablespoon of salt. Refrigerate overnight.

Preheat the oven to 375 degrees. In a bowl, combine the flour, cayenne, paprika, garlic powder, onion powder, pepper and 1 teaspoon of salt. Drain the chicken, pick off the thyme and dredge in the seasoned flour.

In a large ovenproof nonstick skillet, melt the butter in the oil. Add the chicken and cook over high heat until browned, about 5 minutes. Turn and cook for 2 minutes longer. Transfer the chicken to the oven and roast until white throughout, 5 minutes.

Heat the oil in a skillet. Add the onion, cover and cook over moderate heat, stirring, until softened, 5 minutes. Add the thyme and sugar and cook until the onion is caramelized, 15 minutes. Add the sherry and cook until evaporated. Whisk in the chicken stock and dissolved cornstarch and bring to a boil, stirring, until thickened. Season with salt and pepper. Spoon the gravy over the chicken and serve.