Caramelizing plums and peaches on the grill brings out their natural sweetness, and Francis Mallmann bastes them with melted butter and sugar to make them even more luscious. A dollop of cool mascarpone tops the warm fruit. More Fruit Desserts
Light a grill. In a medium saucepan, combine the sliced plums with 3/4 cup of the sugar and the water and bring to a boil. Cover and simmer over moderately low heat until the plums are very soft, about 10 minutes. Transfer the plums to a food processor and puree until smooth. Scrape the plum sauce into a bowl, stir in the lemon juice and set aside.
In a small bowl, stir the melted butter with the remaining 1/4 cup of sugar. Grill the halved plums and peaches over moderate heat, turning once, until the fruit is tender, about 6 minutes. Baste the plums and peaches with the butter and continue to grill, turning once and basting again, until caramelized and slightly charred, about 2 minutes longer.
Transfer the grilled fruit to plates and spoon the plum sauce on top. Dollop the mascarpone alongside the fruit and serve.
The plum sauce can be refrigerated for up to 2 days. Serve warm or at room temperature.