Rinse the shrimp and remove their shells. If you are using frozen shrimp, place them in a strainer and pour warm (but not hot) water over them, and leave to defrost.
Grilled shrimp marinade:
Mix the tomato passata with olive oil and vinegar. Add crushed or finely chopped garlic and basil. Season to taste with salt and cayenne pepper or chilli. You can use flaked chilli or fresh hot chilli peppers - add more (or less) according to how hot you like it. Remember that the power of chilli peppers comes out when heated.
Put the shrimp in the bowl with your marinade, mix thoroughly until fully covered, and put in the fridge for 30 minutes.
Place the marinated shrimps on metal skewers, you can intersperse them with cherry tomatoes or lemon wedges. Grilling time depends on the shrimp size, but try not to grill them for longer than 3 minutes on each side.
Properly cooked shrimp is no longer transparent and has a nice pink colour.