Make the Meatballs:

• In a large bowl, combine ground beef, breadcrumbs, Parmesan, egg, garlic, onion, parsley, salt, and pepper.

• Mix until just combined and form into 1-inch meatballs (about 18–20).

Brown the Meatballs:

• In a large skillet, heat olive oil over medium heat.

• Brown meatballs on all sides (they don’t need to be fully cooked).

• Remove from pan and set aside.

Sauté the Vegetables:

• In the same skillet, melt butter over medium heat.

• Add mushrooms and onions, and cook until softened and golden, about 5–7 minutes.

• Stir in garlic and cook for 1 minute more.

Make the Gravy:

• Sprinkle flour over the mushroom mixture and stir well to coat.

• Gradually whisk in beef broth, then add Worcestershire sauce and thyme.

• Bring to a simmer and cook until thickened, about 5 minutes.

Add the Meatballs:

• Return meatballs to the skillet and reduce heat to low.

• Cover and simmer for 10–15 minutes, or until meatballs are cooked through.

• Stir in cream or sour cream at the end, if using, and adjust seasoning to taste.

Serve:

• Serve hot over mashed potatoes, rice, egg noodles, or crusty bread.

• Garnish with extra parsley, if desired.