This simple technique is prescribed for "tomatoes that aren't as flavorful as you'd like them to be." It's from an everyday-French-food cookbook manuscript I was logging art for at the office this week. It seemed like a good match for our January tomatoes.
My recipe called for halved cherry or grape tomatoes; I used this week's roma tomatoes, cut into thickish slices. They're spread out on a cookie sheet lined with parchment paper.
The recipe said to sprinkle them with salt, pepper, and olive oil. (I also added a little rosemary.) Then just roast them in a 225-degree oven for three hours.
(Okay, I did a 225-degree oven for two hours, then a warming-to-400 oven for about half an hour more -- I had other things to get going for dinner.)
I ate a lot of them off the cookie sheet, but I'm planning to serve these in a salad with this week's mesclun and beets and some goat cheese.
(If you're fancy, call these tomates confites; here's how a more famous food blogger does them.)