For the biscuit base: Preheat the oven to 180C/200C fan. Then blitz the biscuits in a food processor until they resemble fine crumbs. Add the melted butter and blitz until the mixture holds together when pressed with a spatula.
Spoon into each tart case and using the spoon compact against the base and sides. Then bake for 10 minutes, and leave to cool.
For the curd: Peel the zest off the limes (leaving the white pith behind) and place the zest into a medium saucepan. Add in the lime juice, caster sugar and eggs, then place over a medium heat. Whisking continuously (you don’t want the eggs to cook), cook until the curd reaches a simmer. Then take off the heat.
Cut the butter into cubes, and add to a large bowl. Using a sieve, strain the curd over the butter – discarding the zest that is left behind. Stir the curd into the butter until it has completely melted. Then using another bowl, sieve the mixture back and forth three times (discarding any lumps) to ensure you’re left with a smooth curd.
Add a small blob of green food colouring and stir into the curd until combined. Then spoon the curd into the cooled tart shells and place into the fridge for at least 2 hours to set. You can leave them overnight at this point.
Decorating is optional – but when ready to serve, sprinkle some biscuit crumbs in a line over 1/3 of the tart and add sliced strawberries and lime on top, garnishing with the mint.
Tarts will keep for 2 days in an air-tight container in the fridge.