||Preheat a ridged chargrill to moderately high. Brush the lamb with 1 tbsp olive oil and season with salt and pepper. Cook for 4 minutes on each side or until cooked to your liking. Cover and set aside to rest for 5 minutes.
||Meanwhile, pound the anchovy, rosemary, lemon zest and chilli (if using) in a mortar and pestle until you have a thick paste. Slowly pound in 1 tbsp of olive oil.
||Mix the tomatoes, red onion and vinegar with the remaining oil and stir to coat. Season with salt and pepper.
||Serve the lamb with the pounded dressing spooned on top and the tomato salad on the side.