During our visit to Isola Bella we had lunch at Ristorante Elvezia. We ate a club sandwich and a (gluten-free) poke bowl, with some gluten-free bread beforehand. The food was tasty, but the service and atmosphere were significantly less so. The service was quick and very impatient. For a gluten-free dish you can go to Ristorante Elvezia, but the choice is very limited.