Preheat the oven to 400°F (200°C).
In a large mixing bowl, combine the ground beef, breadcrumbs, Parmesan cheese, parsley, egg, minced garlic, onion powder, salt, and pepper. Mix until well combined.
Shape the mixture into meatballs, about 1 to 2 inches in diameter, and place them on a baking sheet.
Bake the meatballs in the preheated oven for 20 minutes, or until browned and cooked through.
While the meatballs are cooking, prepare the cauliflower mash. Cut the cauliflower into florets and boil in salted water for about 10 minutes, or until tender.
Drain the cauliflower and transfer it to a blender or food processor. Add heavy cream, butter, salt, and pepper. Blend until smooth and creamy. Set aside.
For the gravy, heat olive oil in a frying pan over medium heat. Whisk in the flour and cook for 1 minute, stirring constantly.
Gradually add in the beef broth, Worcestershire sauce, and soy sauce while whisking. Bring to a simmer and cook until thickened, about 5 minutes. Season with salt and pepper to taste.
Once the meatballs are done, remove them from the oven and add them to the gravy. Simmer for an additional 5 minutes to combine flavors.
Serve the meatballs and gravy over the creamy cauliflower mash.