To make the base, melt the butter. Process the biscuits in a food processor until they resemble medium-fine crumbs. Add the butter and mix well. Divide the mixture between Le Creuset Petite Casseroles (makes 3 full casseroles or 4 half-filled casseroles). Using the base of a glass, press the biscuit base firmly down to line the bottom and side, making sure it is compact. Set in the fridge for 30 minutes.

For the filling, place the juice, caster sugar and egg yolks into a small saucepan and whisk well to combine. Cook over a low heat, whisking consistently until slightly thickened. Remove from the heat and whisk in the butter. Place back over the heat and continue to cook, stirring consistently until thickened. You will know when the curd is cooked if you run your finger through the back of a spatula or wooden spoon and a path is left in the curd. Taste to make sure there is no raw egg flavour. Stir through the zest and transfer to a bowl. Divide the curd between the casseroles and smooth over the top. Place in the fridge to set for 2-3 hours. Top with a layer of overlapping candied lemons.

To make the candied lemons, slice the lemons 4mm thick (if they are sliced too thinly, they will disintegrate while cooking). Place the sugar and water in a wide saucepan and place over a medium heat. Bring to the boil. Add the lemons in a single layer and simmer in the sugar syrup for 5 minutes. Remove the lemons from the syrup and place them on a flat tray lined with baking paper. Allow to cool. Cut each one in half and scallop over the surface of each mini tart, creating a fish scale pattern. Serve chilled.