1. Place plum tomatoes in a shallow baking dish, drizzle with olive oil and scatter thyme sprigs over all. Season with salt and black pepper to taste.
2. Roast in a preheated 400-degree oven for 15 to 20 minutes, until tomatoes are softened but still retain their shape. Cover loosely with foil and set aside.
3. Reduce oven temperature to 350 degrees.
4. Lay salmon fillets, skin sides down, with some space between them on a baking sheet or baking dish. Season with salt and black pepper to taste and cover with dill. Squeeze ½ of lemon over all.
5. Bake until firm, 15 to 20 minutes.
6. Meanwhile, slice remaining lemon half into ¼-inch slices. Heat a skillet over high heat. Film bottom of pan with olive oil and add lemon slices. Sauté until brown on both sides, about 3 to 4 minutes total. Remove from heat and set aside.
7. Uncover tomatoes. Discard herb sprigs. Place tomatoes on a cutting board and roughly chop.
8. Spoon chopped tomatoes into center of 2 plates. Lay a piece of salmon over tomatoes and lay lemon slices to side of salmon. Serve immediately.