Zucchini skinned, cut in small cubes 1-2cm mix it with salt and leave for 15min. Dry zucchini with cloth.
In separate bowl mix eggs, all cheese and yogurt and zucchini. In other bowl mix sparkling water with oil.
Take filo out from the fridge and unpack. You have to make 4rolls (every roll with 5sheets). Put baking sheet onto the oven tray.
Put one filo sheet on working surface, spread the mixture of oil and sparkling water with basting brush, repeat the process with remaining 4 sheets and on the last 5th sheet spread mixture with zucchini mixture evenly (use around 1/4th of the zucchini sauce so you can have it enough for all 4rolls).
Roll it from the wider side and place in the baking tray. Repeat the process with remaining sheets so you can get 4 rolls.
Make holes with fork on top of every roll and spread some oil / sparkling water mixture on the top.
Bake for 40min in prepared oven on 220C. Cut when cooled down.
Take frozen filo out of freezer night before and put it in the fridge.