Make the batter by putting the flour and salt in a bowl or tray where you can dip the flowers into. Add the milk, then gradually add the water a little at a time and beat with a whisk or fork. Keep adding the water until a thick consistency is reached. Whisk for at least 2 minutes and set aside.
Remove the pistil and stem of the flowers, then rinse gently and dry on paper towel. It’s okay if they tear a little or you open them completely. It’s easier to make sure there’s no dirt or bugs inside this way.
Place a piece of cheese inside each flower. It's okay if a little sticks out, but it's better if the cheese is completely covered. (Add an anchovy on top of the mozzarella, if using.)
Fold the zucchini flower around the cheese. They are very compliant, so this isn't difficult.
At this point, heat a frying pan over medium hight heat with a generous amount of olive oil (no need to deep fry, though.) Next, dip the stuffed zucchini into the batter and coat evenly.
Remove with a fork, let excess batter drip off. Place directly into the hot frying pan. Continue to do this with each stuffed flower.
Fry for a about 2 minutes, then flip over to fry the other side. As you can see, if a little of the cheese oozes it, it won't ruin the end result. When cooked, moved to a paper towel lined plate. Although these can be eaten when cold, they're oh, so much better when they're hot!