To make the lemon mayonnaise, place the mayonnaise, lemon juice and garlic in a bowl and stir to combine. Set aside.
Place the cheeses, breadcrumbs, garlic, butter, salt and pepper in a bowl and mix well to combine. Carefully spoon into the zucchini flowers and gently twist the ends to secure. Place the flour in a bowl and make a well in the centre. Gradually add the chilled water, whisking until smooth.Heat the oil in a large, deep saucepan until hot. Dip the zucchini in the batter and deep-fry in batches for 1 minute or until golden and cooked through. Drain on absorbent paper and serve with lemon mayonnaise. Makes 12.