In theory, this is a very seasonal dessert, great for the start of summer, May bank holidays etc. In reality, it is pretty chilly outside, but I wasn’t going to let that stand in my way!
Using a vegetable peeler, peel off the zest of the lemons in strips, leaving behind any white pith as you would for a martini, then juice the lemons.
Dissolve the sugar in 450ml of water over a low heat until totally dissolved, then add the zest and juice of the lemons and boil for five minutes.
Strain into a jug, discarding the zest. Tip the mascarpone into a bowl, and slowly add the syrup, whisking it in.
Then either make in an ice-cream maker if you have one, or pour it into a large, shallow container and put it in the freezer for 2-3 hours until stiff at the edges.
After this time, take it out, break the edge bits up a little with a fork and use a hand-held blender to whizz all the mixture up together so it’s homogenous, then replace in the freezer. Repeat after another 2-3 hour time period, then put the lid on and freeze completely.