Step 1

Put the Oreos into a food processor and blitz to fine crumbs. Add the butter and blitz again, until the butter is no longer visible and the mixture starts to clump. If you’re doing this by hand, put the Oreos into a sealable bag, crush to crumbs with a rolling pin and tip into a bowl. Melt the butter and stir it into the biscuit crumbs until well mixed.

Step 2

Tip out into a 23 cm-diameter, 3.5 cm-deep loose-bottomed fluted tart tin, and press into the base and up the sides. I find it easiest to use a combination of the back of a large spoon and my fingers. Pop the tart tin in the fridge to chill for 45 mins; when you do so, remove the cream so it’s not fridge-cold when you come to use it.

Step 3

After 20-25 mins, put the white chocolate in a heatproof bowl that will sit on top of a saucepan. Fill the pan with enough water to cover the base by 2-3 cm and bring to a gentle bubble. Sit the bowl of chocolate on top, making absolutely sure it doesn’t touch the water, and turn the heat to low. Let it melt very gently, stirring every now and again with a silicone spatula until only a few lumps remain (about 5 mins). Give it another stir, then take the bowl off the saucepan and leave it to stand for 10-15 mins, until the chocolate has cooled down a bit but is still fluid. If the weather is very warm, it’ll take longer, but I don’t advise putting it in the fridge. You don’t need the white chocolate to be cold; you just don’t want it to be very warm when it’s mixed with the cream.

Step 4

Meanwhile, put the soft cheese into a medium-sized bowl, pour in the double cream and add the pinch of salt. Mix gently but thoroughly, until you have a thick, cohesive, creamy mixture.

Step 5

Add the cooled white chocolate and gently mix again, folding the mixture with a light touch before gradually folding in the white rum, if using. Taste as you go, as you may prefer to use just 2 tbsp of it. (For an alcohol-free version, leave out the rum and instead gently stir in the finely grated zest of ½ lemon and 1 tsp each of lemon juice and vanilla extract.)

Step 6

Take the tart tin out of the fridge and dollop or scrape the white chocolate mixture into the divinely dark chilled tart base, then spread to fill evenly. Put it back into the fridge to cool again for 45 mins to 1 hr, then remove and top with the strawberries and mint.

Step 7

Gently separate the sides of the tin from the base by sitting the tin on a small bowl (I use one that’s 10 cm in diameter at the top and just 6 cm high) and letting the sides come loose. Sometimes, when I’m feeling brave, I swiftly slide a tart off its base and onto a waiting flat plate or board. But this biscuit base is delicate and crumbly, so I find it safer to serve it sitting on its base. Either way, serve within 10-15 mins, as the warmer the tart gets, the more fragile the biscuit base will become.