Make the stuffing by combining the finely grated hard cheese with the soft cheese.
Add the finely chopped herbs, pepper and the zest of a lemon. I usually mash mine together with a fork. This will be easier if your cheese is room temperature.
Make the batter by whisking together your flour, salt, pepper, lemon zest and the juice of the lemon.
Then slowly add the cold water, you may not need all of it, whisking until you have the texture of thick cream. The odd lump is fine and, weirdly, will help you get a nice crunchy batter.
Start warming the oil over medium-high heat. Use a wide, high sided pan. A high sided frying pan is good, a less wide saucepan will mean you can only cook a few in each batch as otherwise, they’ll stick together.
While your oil warms, start to stuff your flowers. You can be "cheffy" and tidy and use a piping bag but I’m never organised enough to use that. I just gently peel one of the flower petals, check for any tiny insects and if I find them, gently remove them. Then I use a teaspoon to squish around a tablespoon of the cheese mixture inside each flower. Then I squish the petals back together so that the cheese is enclosed. A little bit of seepage is fine. The cheese should help the petals stick together if they tear. The first one will feel tricky but you’ll quickly get into a routine. You can stuff the flowers and leave them in the fridge at this stage for a few hours.
Once you have stuffed all your flowers you can test that your oil is hot. I do this by dropping a cube of bread (or a dollop of the leftover batter) in, if it sizzles and starts to turn brown pretty quickly you are ready to fry. If not, leave the bread in and watch until it goes brown.