For each, place one 12—inch-Iong sheet of aluminum foil on top of another. Smear top sheet with 1/2 tablespoon olive oil, and layer a fillet of salmon, 6 tomato halves, salt and pepper, 4 basil leaves and another half tablespoon oil. Add garlic powder on both fillets. Add pepper and salt to taste. Seal package (I like to seal them with skin looking up, to avoid the skin to adhere into the aluminum).
When ready to cook, heat oven. Place packages in a roasting pan. (Or they can be cooked on top of the stove in 2 skillets over medium- high heat.) Cook 5 minutes (for medium-rare) to 8 minutes from the time the mixture starts to sizzle, or roughly 10 to 12 minutes total. Sometimes if the fillet is frozen or refrigerated and it is still cold, I like to cook them for 40 minutes, the melting will bring a lot of flavor with paste created by the cooking process and the water on the fillet.
Use a knife and fork to open the package. Spoon the salmon, garnish and juices onto a plate, and serve.