We were staying further up the Vico Battista for a week, we ate twice here sitting in and as a take away. Both occasions were good. Restaurant has good menu offering local dishes and wine (which the staff will advise on) Food we thought was very good and offered good value. Second time we ordered a Pizza (€4) which was more than for us two and you can get some chilled beer to take away as well. The owner and the staff are very friendly, if in Ischia we would come again.
You may want to book for weekends, as we arrived on Saturday from ferry from Naples and after checking in to our accommodation we wandered down the hill and il Giardino was our first port of call (9.30ish) but they were busy and they had nothing free.