Make mango salad: Whisk together brown sugar and lime juice in a large bowl util sugar is dissolved, then whisk in red chile, shallot, cilantro, and mint. Add mangoes, tossing gently.
Grill shrimp: beginning at thick end, insert a skewer lengthwise through each shrimp to straighten. Transfer to a tray. Prepare grill. Whisk together oil, jalapeno, cumin and salt, then brush on skewered shrimp until well coated. Grill the shrimp, turning occasionally, until lightly charred and just cooked through, about 4 minutes.
Toss mango salad again and divide among 4 plates. Arrange 4 shrimp on top of each serving.
Makes 4 first course servings or two main course servings.