Place the rice, water and butter in a saucepan and bring to the boil. Reduce to a simmer and let the rice absorb the water, stirring occasionally, until all of it has been absorbed.
Meanwhile, combine the rosemary sprigs, milk and caster sugar together in a separate saucepan. Bring to a simmer over a medium heat then add to the rice once it has absorbed all the water. Cook over a low heat for 10-15 minutes, stirring occasionally, until rich and thick.
Meanwhile, pre-heat the grill to hot. Sprinkle the diced apricot with the soft light brown sugar. Grill on a lined baking tray until lightly caramelised. Remove and allow to cool a little.
Stir the chopped pistachios into the risotto then spoon into serving bowls. Top with the apricots and garnish with a few rosemary leaves before serving.