Fill large pot with 2 quarts water and place pot on stovetop over medium-high heat. Bring water to rolling boil.
Once water begins to boil, add 1 tablespoon sea salt and stir to incorporate. Allow water to return to rolling boil.
When water begins to boil again, add 2 cups wide egg noodles. Cook egg noodles 1 to 2 minutes less than time indicated in package instructions, stirring often to prevent sticking.
Pour egg noodles into colander and drain well, then set aside until ready to serve.
For the Mushroom Gravy
Place large skillet on stovetop over medium heat. When skillet is warm, add 4 tablespoons butter. Let butter melt completely, swirling and tilting pan occasionally to distribute butter across surface of skillet.
When butter is melted, add 1 cup minced onion. Sauté onion, stirring frequently, 3 minutes or until softened.
Add 7 cups sliced fresh mushrooms to softened onions. Sauté mushrooms, stirring constantly, 3 to 4 minutes or until mushrooms begin to brown.
Once mushrooms begin to brown, add 1 tablespoon minced garlic and stir to incorporate. Sauté garlic 30 to 60 seconds or until just fragrant, stirring frequently.
When garlic is fragrant, reduce heat to medium-low. Add ¼ cup all-purpose flour, 1 teaspoon salt, and ½ teaspoon cracked fresh black pepper to skillet. Stir to incorporate dry ingredients, then add 1 ¼ cups vegetable broth, ¼ cup dry white wine, and 1 ½ teaspoons Worcestershire sauce.
Stir mixture until all ingredients are fully incorporated, then simmer mixture 5 minutes or until liquids have been absorbed and gravy has thickened.
Remove skillet from heat and let cool slightly, approximately 2 minutes. Add 1 cup full-fat sour cream (at room temperature) and stir until sour cream is fully incorporated. Taste gravy and add more salt and/or pepper as desired.
Return skillet to heat. Add cooked egg noodles to skillet and stir to incorporate. Simmer until gravy has thickened, approximately 2 to 3 minutes.
To Serve
Divide egg noodles between serving plates or bowls. Top noodles with plenty of gravy. Garnish with chopped parsley and additional sour cream if desired. Serve warm.
Recipe Notes
Make it Vegetarian: Use soy sauce instead of Worcestershire sauce.