Fill large pot with 2 quarts water and place on stovetop over medium-high heat. Bring water to rolling boil, then add 1-2 tablespoons salt. Stir to incorporate salt, then allow water to return to boil.
When water begins to boil again, add 2 cups wide egg noodles. Cook egg noodles 1 to 2 minutes less than indicated on package instructions, stirring often to prevent sticking.
Pour al dente egg noodles into colander. Drain well and set aside.
While noodles boil, add ½ teaspoon salt, ¼ teaspoon pepper, and ¼ teaspoon garlic powder to small mixing bowl. Stir until ingredients are well-blended, then set bowl aside.
Spread chicken thigh pieces out on cutting board or other clean, flat surface. Sprinkle spice mixture over chicken thigh pieces, coating all sides of chicken thighs well. Set chicken aside.
Heat large skillet over medium heat. When skillet is warm, add 3 tablespoons butter. Melt butter, swirling pan occasionally to distribute butter across entire surface.
When butter is melted, add minced onion. Sauté onion, stirring often, 2 minutes or until slightly soft.
When onion has softened, add sliced mushrooms and cook, stirring constantly, 3 to 4 minutes or until mushrooms begin to brown.
Once mushrooms begin to brown, add minced garlic. Cook, stirring frequently, 30 to 60 seconds or until garlic is fragrant.
When garlic is fragrant, add remaining 1 tablespoon butter, seasoned chicken thigh pieces, ¼ cup all-purpose flour, remaining ½ teaspoon salt, and remaining ¼ teaspoon pepper to skillet. Stir to incorporate, then cook, stirring constantly, 3 to 4 minutes or until chicken pieces have browned.
Once chicken has browned, add 1 ¼ cups chicken broth, ¼ cup dry white wine, and 1 ½ teaspoons Worcestershire sauce to skillet. Stir to incorporate, then bring mixture to gentle simmer. Simmer over medium heat 5 minutes or until liquids have thickened.
Remove skillet from heat and let cool slightly. Add sour cream and stir gently until sour cream is fully incorporated. Taste sauce and season with additional salt and pepper if desired.
Return skillet to heat. Simmer over medium-low heat until chicken is cooked through, approximately 2 to 3 minutes.
When chicken is fully cooked, divide cooked egg noodles between serving plates or bowls. Top noodles with chicken pieces and plenty of sauce. Garnish with chopped parsley, additional sour cream, and paprika if desired. Serve warm.