COURGETTE AND LEMON ORZO WITH GARLIC PRAWNS

2 tbsp olive oil • 600g courgettes, halved lengthways and cut into 0.5cm slices • 2 onions, finely chopped • 175ml dry white wine • 300g orzo pasta • 1 litre chicken or vegetable stock • 50g unsalted butter • 4 garlic cloves, finely chopped • 2 x 180g packs raw large king prawns, veins removed • ½ tsp sweet smoked paprika • 1 lemon, juice • ½ x 25g pack flat leaf parsley, finely chopped