Pick and finely chop the leaves from 2 rosemary sprigs. Put in a bowl with the deseeded and finely chopped red chilli, 1 crushed garlic clove (if you like) and 1 tbsp olive oil. Add the shrimp, season, turn to coat then leave to marinate for 10 minutes.
Set a large griddle pan over a medium-high heat. Fry the marinated shrimp for 2-3 minutes until lightly charred and cooked through.
To serve, divide the citrus fruit and kale salad and the prawns between two plates.