In a large pot, cover peaches with water (about 2 cups). Add mint, salt and white pepper, and bring to a simmer. Cook until peaches are very tender and flavors infuse, Remove from heat and cool to room temperature.
Remove mint sprigs, and with an immersion blender (if the pot is big and deep enough), or in batches in a blender, to avoid a major blender explosion, puree the peaches. Add mango juice and cream and blend. Adjust salt and pepper if needed, and chill.
Ladle into serving bowls and serve garnished with mint sprigs.