In a large bowl, combine all of meatball ingredients and mix until well combined. Roll the meatballs into balls (equally sized). I made mine about 2 tbsp in size (makes about 20-22).
In a large, high-walled skillet, heat 1-2 tbsp of oil over medium-high heat. Add half of your meatballs, cooking in 2 batches to ensure that they aren’t overcrowded. Cook the meatballs until they are browned on all sides and mostly cooked through (they will finish cooking in the oven later). Repeat steps for the second half of meatballs, adding more olive oil if necessary.
Set the cooked meatballs aside. Add 5 tbsp of butter to the skillet and melt. Slowly add the flour, whisking constantly until the flour is fully incorporated. Cook the flour for 2-3 minutes, continuing to whisk constantly.
Add the beef broth, sour cream, heavy cream (or milk), Worcestershire sauce, Dijon mustard, garlic powder, and about 1/2 tsp each of salt and pepper. Bring the sauce to a simmer, and then lower heat to medium-low. Continue to cook the sauce at a gentle simmer until it thickens slightly, about 5 minutes.
While the sauce is thickening, cook the egg noodles according to package instructions (Error on the al dente side). Once they are cooked, return the noodles to the pot and add 1 tbsp of butter (or more if you’re feeling frisky) to the noodles and toss them until they are coated in the butter. Pour the buttered noodles into a casserole dish and preheat your oven to 350 degrees.
After the sauce has thickened, add the meatballs back to the sauce, and roll them around until they are coated in the sauce. Use a spoon or a pair of tongs and gently transfer the meatballs to the casserole dish, nestling them into the noodles. Carefully pour the sauce evenly over the meatballs and noodles.
Top the meatballs with cheese and cook in the oven for 10-15 minutes until the meatballs are cooked completely through and the cheese is nice and melted. Top with chopped fresh parsley and serve. Enjoy!