Preheat the oven to 400°. Place onions and shallots on a quarter size rimmed baking sheet, drizzle with 2 tablespoons of the olive oil and season with salt and pepper. On a half sheet rimmed baking sheet, add tomatoes, gently coat with the remaining oil and sprinkle with salt and pepper. Drizzle vinegar and sprinkle minced rosemary on them. On a separate rack, roast onions, shallots and tomatoes for about 30 minutes, or until soft, browned, juicy and tomatoes skins are wrinkled.
Tent the baking sheets to keep the produce warm with aluminum foil and wait for 10 minutes before serving. This compote will be good to serve with any kind of protein.
Recipe by Flavor and Friends at http://flavorandfriends.com/cherry-tomato-compote-sweet-onion-rosemary/