01 - In a large mixing bowl, combine ground beef, breadcrumbs, milk, egg, chopped onion, minced garlic, Parmesan cheese, parsley, salt, and black pepper. Mix gently until just combined, being careful not to overwork the meat.
02 - Roll the mixture into 1 1/2-inch meatballs, yielding approximately 20 to 24 uniform portions.
03 - Heat a thin layer of oil in a skillet over medium-high heat. Brown the meatballs in batches, turning every 2 to 3 minutes per side until a golden crust forms. This step enhances both texture and depth of flavor.
04 - Arrange the meatballs in a single layer at the bottom of the crockpot.
05 - In a separate bowl, whisk together beef broth, cream of mushroom soup, Worcestershire sauce, soy sauce, dried thyme, onion powder, and garlic powder until smooth. Pour the mixture evenly over the meatballs.
06 - Cover and cook on LOW for 4 to 5 hours or on HIGH for 2 to 3 hours, until the meatballs are cooked through and tender.
07 - Stir in the heavy cream. If the gravy needs thickening, add the cornstarch slurry and stir well. Cook on HIGH for an additional 10 to 15 minutes until the gravy reaches the desired consistency.
08 - Taste and adjust seasoning as needed. Serve hot over mashed potatoes, egg noodles, or steamed rice.