Combine cheese, herbs, and a little nutmeg in a bowl. Taste and check if it requires more salt.
Gently ply open the zucchini flower petals to check for insects and remove stamen or pistil.
Cut the corner from a plastic freezer bag to make a piping bag. Add the cheese mix to the bad and squeeze through the hole into the flowers. Set aside.
Heat oil in a saucepan. You will know it is hot enough when bubbles appear on the back of a wooden spoon that is dipped in the oil.
While the oil is heating place flour in a bowl and then whisk in the cold mineral water. Don’t get too pedantic about small lumps.
Dip the stuffed zucchini flowers into the batter and then remove giving them a little twirl allowing the excess batter to drip off.
Deep fry immediately in hot oil.
Scatter with a little extra grated parmesan and serve