Step 1: Cook the Egg Noodles

1. Bring a large pot of salted water to a boil.
2. Add the egg noodles and cook according to package instructions until al dente.
3. Drain and set aside.

Step 2: Brown the Ground Beef

1. Heat a large skillet or Dutch oven over medium-high heat.
2. Add the ground beef and cook until browned, breaking it into small pieces with a wooden spoon.
3. Once cooked, remove the beef from the skillet and set aside. Drain excess fat if needed.

Step 3: Sauté the Vegetables

1. In the same skillet, add olive oil or butter.
2. Sauté the chopped onion until translucent (about 3-4 minutes).
3. Add the minced garlic and sliced mushrooms, cooking until the mushrooms are tender and golden (5-7 minutes).

Step 4: Make the Sauce

1. Sprinkle the flour over the mushroom mixture and stir to combine. Cook for 1-2 minutes to remove the raw flour taste.
2. Gradually pour in the beef broth, stirring constantly to avoid lumps.
3. Add the paprika, Worcestershire sauce, Dijon mustard (if using), salt, and pepper. Bring to a simmer and let the sauce thicken slightly.

Step 5: Combine and Finish

1. Return the cooked ground beef to the skillet and stir to combine.
2. Reduce the heat to low and stir in the sour cream until the sauce is creamy and well-incorporated.
3. Taste and adjust seasoning if needed.