Preheat oven to 300 degrees F (149 C) and line 1 large (or 2 small) baking sheet(s) with parchment paper (increase number of baking sheets if making a larger batch).
Add tomatoes and drizzle with oil and sprinkle with salt (and pepper if adding). Arrange face up and roast for 1 hour to 1 hour 45 minutes. The longer they bake, the more shriveled the tomatoes become and the more intense the flavor will be.
Enjoy immediately as is, or with pasta, pizza, salads, soups, and more!