In a bowl, place the shrimp, ginger, garlic, coriander seeds, olive oil, and orange juice. Mix well and set aside to marinate for 15 minutes.
In a pot, heat a little olive oil and sauté the onion and garlic until golden. Add the mango, orange juice, and vinegar. Cook over medium heat for 15 minutes. Transfer the mixture to a blender and process until smooth. Force through a fine strainer, adjust the salt and pepper, and set aside.
Thread the shrimp onto skewers and grill over high heat for 3 minutes per side.