Cut the chicken into 1-inch strips, placing them into a bowl. Season with garlic powder, onion powder, paprika, crushed red pepper flakes, thyme, and 1/2 teaspoon each of salt and pepper. Toss thoroughly to combine.
Drizzle in about 1 tablespoon of the oil into a preheated dutch oven, and cook the chicken in batches, being careful not to overcrowd the pan. Brown the chicken about 2to 5 minutes on each side. Do not worry about cooking it all the way, this step is just to develop color and flavor. Continue sauteéing the chicken, in batches, until it is all browned. Transfer the finished pieces onto a plate to rest.
Throw in the remaining tablespoon of oil and add the chopped onions and garlic to the pot. Stir occasionally and allow to caramelize until the onions are soft and translucent. Add the sliced mushrooms. Season with a pinch of salt and pepper and stir coating the mushrooms completely with the oil, onions and garlic. Cook for about 5 minutes, or until the mushrooms are browned. Make a well in the center of the pot. Add the butter and flour, mixing together to make a roux. Cook for about 1 minute to let the raw flour taste cook off. Then, stream in the chicken stock while you mix everything together. Add the Worcestershire sauce and stir once more. Lower the heat to low and allow the sauce to thicken and bubble slightly. Throw in the chicken, along with the juices, and continue to cook, on a simmer, for about 5 to 10 minutes. In the meantime, follow the instructions on the egg noodle package to cook. Pasta should be slightly tender or "al dente." Drain and let sit for a minute while you finish the sauce.
To the sauce and chicken, add the sour cream, and season once more with a pinch of salt and pepper. Stir together and bring to a simmer. Toss in the egg noodles and sprinkle with the chopped parsley for garnish. Or you can arrange the cooked pasta on a serving platter and just spoon over the chicken stroganoff on top. Garnish with a dollop of sour cream and chopped parsley. Serve right away. Stroganoff can be made in advance and stored in the fridge. When ready to serve, just reheat on the stove and cook the noodles, then simply toss together. Enjoy!