To me, fish should always be cooked whole - i.e. with head and tail on. It is the secret to a juicy and moist texture, and it is the best way to preserve the flavours. This snapper is roasted with a very simple stuffing of fresh herbs and lemon, and then filleted and served on an equally simple bath of cooked grape tomatoes and black olives. The key is to have enough juice from the tomatoes on the bottom of your bowl, so that you will be able to dip each mouthful of snapper in it! —Silvia Merler
Rinse the snapper and pat dry with paper towels. Cut two thin round lemon slices and insert them in the fish's cavity together with 1 spring of fresh rosemary and one spring of fresh thyme. Sprinkle the inside with about 1/4 tsp of salt. Lay the fish on a baking sheet lined with parchment paper and bake for 40-45 minutes, turning the baking sheet once about halfway through cooking time. As a general rule, a whole fish is done when the eye turn from transparent to white and the eyeball slightly pops out. This may occur earlier if your fish is smaller, so if that happens take it out of the oven (you do not want to overcook).
While the fish is in the oven, prepare the sauce. In a sauté pan (or frying pan for which you have a lid) heat 2 tablespoons of olive oil on medium-high heat. Add the diced onions, the olives, one spring of thyme and one spring of rosemary. Cook for a couple of minutes stirring often, then add the tomatoes. Cook for a couple of minutes on medium-high heat, then remove the springs of rosemary and thyme with a slotted spoon, add 1/2 cup of water, wait till it starts boiling, cover with the lid and turn to low heat. Let the tomatoes cook on low heat for 20 more minutes. Check and add water, necessary. The idea is to have in the end tender and cooked through tomatoes, with at least 1/2 of liquid juice. Add salt and pepper to taste (it depends also on how salty the olives you are using).
When the fish is ready, take it out of the oven and let it rest for 5 minutes, then remove skin, head and bones - which can be used to make fish stock - and fillet it. To serve, I normally use two deep bowl (the kind you would eat ramen in). Distribute some tomatoes and juice on the bottom, top with fish fillets, then add the rest of the tomatoes and juice. Squeeze a few drops of lemon juice on top and serve.