In a large bowl, mix the salt with the sugar. Toss the lemons with half of the sugar-salt. Pour a small layer of sugar-salt into a clean quart-size jar.

Add this to your steeped lemon peel and vodka and leave for at least one more week. To make the lemon syrup, place the lemon rind and juice in a small pan with the sugar and 100ml/3½fl oz water.

Whisk together ricotta cheese, spreadable cheese, egg, lemon zest, salt, and 1/2 cup Parmesan in a medium bowl until well combined and smooth; stir in spinach.