Call the restaurant.
Agree with Douglas and Ray,ask the Kitchen . Doubtful there would NOT be onions integrated into the recipe
You should contact La Toscana by phone to find out the answer to your question. Depending on the internet to get answers for health related questions should be avoided.
I had the meatball appetizer and it wasn't 'oniony', it was excellent! You should call the restaurant directly.
Thanks! Your answer is awaiting moderation.