In a glass dish, mix together the olive oil, mustard, garlic, lemon juice, orange juice, basil and white wine. Add the prawns, and stir to coat. Cover, and let marinate for 1 hour.
Heat an outdoor grill to high heat.
Thread prawns onto skewers. Grill for 3 to 5 minutes, turning once, until pink.
If desired, reserve marinade; transfer to a saucepan and bring to a boil. Reduce heat and simmer for 5 minutes. Serve with prawns.
