Peel the prawns, removing the heads and leaving the tails on. Run the tip of a knife down the backs of the peeled prawns and pull out and discard the dark vein. Peel the garlic and finely chop with the chilli (deseed if you like). Pick and finely chop the parsley leaves. Drizzle the oil into a shallow heatproof terracotta dish or a small frying pan over a medium-high heat, add the garlic and chilli and fry for 30 seconds to flavour the oil, before stirring in the paprika. Add the prawns and fry for 2 minutes on each side, or until cooked through, adding most of the parsley when you turn the prawns. Squeeze half the lemon juice into the dish, then remove from the heat and sprinkle over the remaining parsley and a pinch of sea salt. Serve sizzling with warm crusty bread, the remaining lemon cut wedges for squeezing over, and a glass of good Spanish wine.