For the dressing, add lime juice, olive oil, capsicum and chives in a small bowl and swirl to combine. Set aside.
For the prawns, add oil and butter to a large frying pan on high heat. Once butter has melted, add garlic and lime juice. Add the prawns and toss, making sure they are all evenly covered in butter. Remove from frying pan and set aside.
To make the salad, place salad greens, mango, avocado and prawns to a large bowl and pour over dressing. Toss thoroughly to combine and serve.