Line a 2lb loaf tin with cling film
Remove the stones from the cherries and put them in a pan with the sugar. Set over medium heat and stir occasionally until the sugar has dissolved. Bring to the boil, then lower the temperature and simmer for a couple of minutes to draw out the cherry juice. Break down some of the cherries with a wooden spoon. Cook for 5 minutes then remove from the heat. Stir in the cherry jam and pour into a bowl and chill in the fridge.
In a large mixing bowl, whip the cream with electric beaters until thick soft peaks form.
Pour in the condensed milk, vodka and lime juice, and gently fold together. Of course, taste some, you would have to be made from marble to resist.
Pour the ice cream mixture into the loaf tin. Spoon half of the cooled cherries on top, then, using a skewer or something thin (I used a temperature probe) swirl and ripple the cherries through the ice cream. Repeat with the rest of the cherries, making sure there's enough on the surface.
Cover with another sheet of cling film, then place in the freezer for 6 hours or until frozen. Scoop into ice cream glasses or bowls and serve with some crumbled speculoos biscuits.