Chop the flesh of the mango and cucumber into small pieces. Slice the scallions (the white section and ¾ of the green). De-seed the chilli and chop very finely. Place everything into a small mixing bowl.
Cut the passion fruit in half and empty the juice and seeds into the mixing bowl using a small spoon. Add the finely grated zest of 1 lime and 4 tablespoons lime juice. Add the fish sauce, mix and season to taste. Cover and leave to rest in the fridge for 30 minutes if possible.
Take the lamb out of the fridge 30 minutes in advance of cooking. Pre-heat a frying pan on a high heat. Brush the lamb with garlic-infused olive oil, season with salt and pepper and place in the pan. Cook for 2 minutes on each side, then reduce the heat and continue to cook depending on your preference and the thickness of the cut.
Serve with the salsa and crusty bread.