Start by making the batter. Put the flour, salt and pepper in a bowl. Start turning with a fork.
Gradually add the very cold sparkling water from the fridge in the center and stir first with a fork and then with a hand whisk and quickly to create a thick and smooth batter, without lumps. The batter must have a consistency that is not too liquid but at the same time not too thick, it must remain attached to the courgette flowers when you dip them.
Rinse the flowers in cold water, dry them well, then remove the internal pistils. Let's move on to the filling of the courgette flowers, inserting the mozzarella and continue to stuff the flowers with the cubes of cooked ham. Put the flowers, one at a time, into the batter, make it adhere well everywhere, then dip them, always 1 at a time, into the hot oil.
Cook until golden brown, drain, drain on kitchen paper, then season the fried zucchini flowers with salt and pepper and serve immediately.