In a large bowl, combine ground beef, grated onion, arborio rice, chopped parsley, dill, one egg, dried oregano, salt, and pepper. Mix gently until just combined.

Shape the mixture into golf ball-sized meatballs and chill in the refrigerator for 15–20 minutes.

Bring chicken broth and olive oil to a gentle simmer. Add the chilled meatballs, cover, and cook for 30 minutes.

Whisk together eggs and lemon juice, then temper with hot broth before stirring into the meatball pot.

Stir gently and heat until the sauce thickens slightly without boiling.

Serve warm, garnished with additional dill or lemon wedges, alongside crusty bread or rice.