Making Meatball Marsala is easier than you think with this recipe. You will make the meatballs first. Mix ground beef, sweet Italian sausage, breadcrumbs, egg, chicken broth, kosher salt and black pepper in a bowl. Roll the mixture into similarly sized meatballs and add them to a baking sheet lined with parchment paper. Broil the meatballs for seven minutes until cooked through. For the Marsala sauce, melt butter in a saucepan. Add mixed mushrooms and cook until browned. Then add kosher salt, black pepper, all-purpose flour, Marsala wine and chicken broth. Stir well until all ingredients are combined. Add the meatballs to the sauce, then add chopped fresh parsley to the mix and stir. Serve over mashed potatoes and add more parsley for garnish as desired.