Place a flambé pan on a rechaud (tabletop stove) or stovetop set to high heat. Pour red wine to fill roughly 1cm deep, stir in the sugar, add the drained peaches, and drizzle with lemon juice and some of the rum.
Heat on high heat for 3-5 minutes, continuously spooning or tilting the pan to baste the peaches with the wine sauce, until the mixture is steaming.
Remove the pan from heat. In a ladle, heat the remaining rum (roughly 2-3 tablespoons) over a flame for 1-2 minutes until ignited. Carefully pour the flaming rum over the fruit in the pan.
Once the flames subside, divide the flambéed peaches and sauce between serving bowls. Top with sliced almonds and grated chocolate.