There are many different approaches to making and using roasted tomatoes. Here's another one, optimal for plum tomatoes - small to medium sized and not excessively juicy. The result is excellent ground or pureed into a pasty sauce and applied to pasta, roasted meat, or vegetables. Alternatively, you can freeze the roasted tomatoes for later use.
4-6 cups plum tomatoes or similar
Good quality olive oil
Salt and pepper
Dried herbs: optional
Preheat the oven to 300 degrees.
Slice the tomatoes in half lengthwise and core and seed. Spread them out cut side up on a rimmed baking sheet. You may wish to line it with parchment or a silicone baking mat.
Drizzle the tomatoes generously with olive oil. Sprinkle with salt and pepper, generously but not to excess. If desired, you may also sprinkle with one or more dried herbs: basil, oregano, sage, rosemary, and/or thyme would all work well.
Roast the tomatoes for an hour, or a bit longer if they are on the large side. When they are done, they will have mostly collapsed and slightly caramelized; they will still be somewhat moist but not juicy,