Do you mean oven-dried tomatoes?
You don't actually 'roast' them, just dry them out at meringue-temperature for hours & hours (until they get a bit theathery), then put them in a jar and cover well with olive oil. We've still got some from the year before last and they're fine. Roma are good for this because they are hollow inside.
Or you can really roast them and then turn them into puree. Cut in half, put on a roasting tray with olive oil, salt, herbs, garlic & stuff; roast till done; liquidise & seive; use or freeze.