My love and I have recently fried courgette flowers. We always thought that they are so expensive and complicated to make but we were proven wrong. 8 pieces just cost 2 € (at least where we bought them this time of the year), but the price may vary. My sweetheart prepared the beer batter so I can't tell you much about it despite that it contains beer, flour, baking soda, egg whites and a hint of salt. But you'll find many recipes on the internet.
And then the even easier part begins. Whisk the flower through the batter and put it into hot oil for frying. We used sunflower oil. I would advice you to decide for a small pot as you don't waste too much oil this way.
Beer battered courgette flowers are amazing on top of salads or just as a snack. They taste soooo good!!