Thanks about advice (yes, I might knew it already but thanks for reminding me). I have already made zucchini lasagna and today I made filled zucchinis (one half filled with browned groud beef, tomato sauce, olives, tomatoes, basil and grated cheese, the other half with tuna in curry sauce, boiled potato, tomatoes, sage and grated cheese). My workmate promised to write to me also a recipe for zucchini cookies. I need to try it next then.