Make sure the prawns are peeled, and deveined and the tails are left on. Pat them dry with paper towels and season lightly with salt and pepper.
In a large skillet, heat the olive oil over medium heat. Add the sliced garlic and sauté for 5-7 minutes in low heat. Cook the garlic until it becomes fragrant and starts to turn golden, but be careful not to let it burn, which can make it bitter. Add chili flakes and paprika powder.
Add the prawns to the skillet with the garlic and oil. Cook for 1-2 minutes on each side until they turn pink and opaque. Be sure not to overcook them, as they can become rubbery.
Season with salt and pepper and remove from heat. Squeeze in the lemon juice and finally add the chopped fresh parsley over the prawns and garlic.
Gambas al Ajillo is best served hot right from the skillet. Transfer the prawns and garlic to a serving dish, making sure to pour the flavorful oil and garlic over the top.
Serve the prawns with crusty bread to soak up the delicious garlic-infused oil. You can also drizzle some of the oil over the bread for extra flavour.