To make the chutney, heat 2 tablespoons olive oil a medium sauce pan over medium heat. Add onions and cook until golden and caramelized, about 8-10 minutes. Stir in chili flakes, ginger, mango, curry powder, honey, white wine vinegar and water.
Bring mixture to a boil, reduce to a simmer and cook until liquid has reduced by half and chutney has thickened, about 25-30 minutes. Remove from heat and stir in lemon zest and mint. Allow to cool to room temperature, then transfer to a jar and seal it tightly before refrigerating.