Preheat oven to 400° F (200° C). Rinse fish, and pat dry. Sprinkle salmon with olive oil, salt, black pepper. Place fillet on a large sheet of aluminum foil. Top with a sprig of thyme on the top and squeeze the juice from the ends of the lemons over the fish. Arrange lemon slices on top of fillets. Carefully seal all edges of the foil to form enclosed packets. Place the packet on a baking sheet.
Bake in preheated oven for 20 to 25 minutes, depending on the size of fish. Fish is ready when it flakes easily with a fork. Enjoy your meal!!!