Bring a large pot of water to a boil for egg noodles and cook according to package instructions. (Drop noodles after you add the mushrooms to the turkey mixture, and they should both end up done about the same time.)

Heat oil in a large skillet over medium heat. Add diced onion and cook until slightly softened and golden brown, about 3-5 minutes.

Add ground turkey and season with salt and pepper. Break up with a spatula or the back of a spoon into small crumbles. Cook until almost cooked through, about 3-4 minutes.

Add sliced mushrooms and garlic to the turkey and stir to combine. Cook for another 5 minutes, until mushrooms start to soften and have released their moisture (mixture will look wet).

Sprinkle turkey and mushrooms with flour and stir into the turkey mixture until it’s coated. Pour in broth, cream, Worcestershire sauce, and Dijon mustard and stir to combine. Bring to a simmer, turn down the heat to low, and stir frequently. Let cook 5-10 minutes, until mixture has thickened, but is still saucy. ***If your burner runs hot, this may cook faster.

Stir in sour cream, remove from heat, and serve over egg noodles. Top with flaky salt and freshly cracked pepper to taste.