Bake meatballs on a sheet pan for 20 minutes at 350°
While the meatballs are cooking, melt 1/4 cup of butter in a saucepan over medium-high heat. Once butter is melted, whisk in 1/3 cup of all-purpose flour and continue to whisk until it browns up and thickens a bit. Slowly stir in 4 cups of beef broth and whisk while cooking for 2 minutes, or until it starts to thicken. Once the sauce has thickened, add 3/4 cup of sour cream and stir well. Now add your baked meatballs to the sauce and let cook for 10 minutes. Salt and pepper to taste. Serve immediately over cooked egg noodles.