Preheat the oven to 400 degrees F. Line a large rimmed baking sheet with aluminum foil.
Prepare the meatballs: crack the egg into a large bowl and beat lightly with a fork. Add the remaining meatball ingredients and mix until well combined. Drop rounded tablespoon sized balls of mixture onto the prepared baking sheet. Roll lightly in your hands to shape. This should make 20-25 meatballs. Bake for 15 minutes or until meatballs reach an internal temperature of 165 degrees F.
While the meatballs are baking, cook your pasta according to package directions. Drain and set aside when finished.
When the meatballs have about 10 minutes left, start preparing the alfredo sauce. Melt the butter on low-medium heat. When the butter is melted add the flour and cook for about 2 minutes until bubbly and flour begins to turn golden. Add milk and garlic powder and heat milk for 1-2 minutes, stirring.
Remove from heat, then whisk in Greek yogurt ¼ cup at a time. Once milk and yogurt are smooth, put the pan back on low heat and add the salt and pepper. Add parmesan cheese gradually, stirring to melt before adding more. Add any additional salt and pepper to taste.
Combine cooked meatballs and alfredo. Serve over pasta of choice with roasted or air-fried broccoli.