Today I had lunch with my son at Delio's Cantina that is located at Alto da XV Disctrict. I had a nice Fiorentina Steak and he had a Garlic Fettuccine. Both perfect!
This is a very casual restaurant, tastefully decorated (with curios objects hanging on the ceiling and walls), the service is above average (they are really concerned with customer's satisfaction), the food is VERY good and the price is fair.
The owner of the Delio's Cantina, also owns the Bella Banoffi confectionery across the street and the Cana Benta Bar (on the same block), they form a triplet that values the Alto da XV disctrict as a good gastronomic choice in Curitiba.