In a small bowl, mix together the lemon zest and 2 tsp lemon juice with the chilli, garlic and oil. Season with salt and freshly ground black pepper.
Cut small slits on one side of each sardine. Rub the lemon and oil mixture all over the sardines, rubbing well into the slits and body cavity.
Cook the sardines on a preheated barbecue (or over a medium-high heat in a griddle pan) for 3 minutes each side, until cooked through and the flesh flakes away easily from the bone. Put the lemon halves, cut-side-down, next to the fish for the final 3 minutes of the cooking time.
Serve the sardines with a few drops of Tabasco, the grilled lemon halves and the mixed salad.