Scrumptious Lemon and Lime Tart

When it comes to making puddings or desserts when friends or family are coming over, I find it hard to stray from anything with chocolate. You just know that chocolate will be a winner with everyone, don't you? But a while ago my Mum shared with me this recipe, and declared it to be both utterly delicious, and extremely simple. I had to give it a try.

If you're wondering whether a lemon and lime tart might be, well, a little bit too tart and zingy - do not worry! This tart has a lovely zing, but also a creaminess and sweetness that offsets the zing perfectly. The other great news is that although it requires a bit of time in the freezer and the fridge, the actual preparation (you can't even call it cooking - the only thing that gets hot is the butter!) can be done in about 20 minutes maximum.

Ingredients

• 275g oat biscuits
• 75g unsalted butter 
• 2 medium lemons 
• 2 limes 
• 397g can sweetened condensed milk 
• 200ml double cream 
• Reserve some of the lime and lemon zest, to decorate

Method

1. To make the biscuit base, break the biscuits into chunky pieces and blitz into crumbs in a food processor. Melt the butter in a small saucepan and add to the crumbs with the motor running. Blend until evenly combined. Alternatively, put the biscuits into a plastic bag and give them a good bash with a rolling pin until all you have is crumbs. Add the butter and stir until the biscuits and the butter starts to come together.
2. Press the biscuit crumbs onto the base and the sides of a 23cm loose-based tin that is at least 3.5cm deep. Make sure you push the crumbs right into the corners. Cover with cling film and freeze for 30 minutes.
3. Finely grate the zest from the lemons and limes and squeeze the juice. You’ll need exactly 125ml of juice for the filling to set.
4. Beat the condensed milk and cream together in a large bowl using an electric whisk for at least 3 minutes or until it begins to thicken. Set aside 1 teaspoon of citrus zest for decoration. Add the rest of the lemon and lime zest and all the juice to the condensed milk and cream and whip for just a few seconds more. The mixture will thicken quickly. 
5. Take the biscuit base out of the freezer and remove the cling film. Immediately spoon the topping onto biscuit base. Swirl the surface with the back of a spoon. Sprinkle with the reserved lemon and lime zest. Cover the filled biscuit base loosely with cling film and chill for 1 to 2 hours before serving.

You can also freeze this tart - it will keep for up to 1 month. Open freeze the filled biscuit base for 2 hours then double wrap in foil and return to the freezer. You can remove the tart from the loose bottom tin and double wrap in foil as soon as it is solid. To defrost, transfer it to a serving plate, cover loosely and leave to thaw at room temperature for 1½ - 2 hours.