In a bowl, mix together the pork, basil, pepper, lemon zest, breadcrumbs, and egg. Shape into small meatballs of 2 cm in diameter. Set aside. In a pot, bring the beef broth to a boil and add the meatballs. Cook the meatballs for 15 minutes. Once cooked, remove the meatballs and set aside to keep warm. Dissolve the cornstarch in cold water, add to the broth, and bring to a boil. Cook for 5 minutes. Add the lemon juice. Serve the meatballs on a bed of garlic butter pasta, drizzle with broth, and serve.