First remove the tails from the prawns, de-vein them and pat dry with kitchen paper and set aside.
Melt the butter and oil in a large pan over medium high heat until lightly golden. Add the garlic and fry for 1-2 minutes, then stir in the prawns and toss in the pan continuously until lightly golden.
Pour the white wine into the pan to deglaze it and stir for a few minutes on a medium to high heat.
To make the dressing whisk together the olive oil, the lemon juice and season with salt and pepper. Toss the salad leaves in the dressing until lightly coated.
To serve, place some salad leaves on a plate and arrange the prawns around it. Serve immediately.