For the marinade

1. Mix. In a medium bowl, whisk all the marinade ingredients together until evenly mixed.

For grilling

1. Prep shrimp. In a large bowl, add the shrimp and drizzle with 3 tablespoons of the marinade. Toss to coat the shrimp evenly. Reserve the remaining marinade for brushing on the mangos and grilled shrimp. Let the shrimp sit at room temperature for 15 minutes while preparing the mangos.
2. Prep mangos. Remove the flesh from the mangos by cutting lengthwise, slightly off center, down the wide sides of the mangos avoiding the seed in the center (you’ll have some flesh left on the mango seeds which you can snack on). You should end up with 4 large mango slices. Score the flesh of each slice in a diamond pattern being careful to not cut through the skin. Set aside.
3. Prep grill. Heat the grill to high.
4. Skewer shrimp. Thread shrimp onto skewers and lightly brush each side with some oil (see Note 1). Brush some marinade onto the scored side of the mango slices.
5. Grill. Lay shrimp skewers and mangos (cut side down) on grill.
6. Cook shrimp. Grill shrimp (turning once) until they are bright pink and just opaque in center, 4 to 6 minutes total. Brush shrimp on both sides with reserved marinade during the last minute of cooking.
7. Cook mangos. Grill mangos until slightly charred and grill marks appear, about 5 minutes (see Note 2).