Cut three shallow diagonal slits into the skin on each side of the fish and carefully drizzle a little oil over the skin, gently rubbing it over the fish until it’s completely coated in oil. Season the cavity of the fish with salt and pepper, then stuff it with most of the lemon, garlic and rosemary, along with the shallot, and finish with a little drizzle of olive oil to coat it all. Put the fish into a roasting tray.
Place a sliver of garlic and lemon and some rosemary in each of the diagonal slits. Sprinkle salt over the skin on both sides, then place the fish in the oven and
While the fish cooks, make a little salad. Place the lettuce leaves in a small bowl and roughly grate the carrot on top, then garnish with the drained, chopped shallot. Drizzle oil and vinegar over the salad, to taste.
Remove the fish from the oven and eat while hot, with the salad.