Olive Oil Slow-Roasted Tomatoes with Garlic

olive oil slow-roasted tomatoes in a gratin dish

Get ready for a rich and tender flavor bomb in your mouth. So much so, if you close your eyes and eat one of these olive oil slow-roasted tomatoes, it makes you think you are in Italy. Plus, they are the perfect way to preserve lots of garden-fresh tomatoes, no canning required.


  • 4 extra-large or 8 small garlic cloves, smashed, peels removed
  • 1 can (3.75 ounces) sardines, finely chopped (optional)*
  • 2 lbs garden-fresh paste tomatoes, cored
  • kosher salt for sprinkling
  • 1/3 cup (118 ml) olive oil


  1. Preheat the oven to 300°F (148°C). Position the baking rack in the middle of the oven.
  2. Arrange the garlic and sardines (if using). Scatter the smashed garlic cloves and sardines across the bottom of a shallow 2-3 quart baking dish* (see the note above in “Tips for Success”)
  3. Cut the tomatoes. Cut smaller-size tomatoes into thirds lengthwise, or if you have larger paste tomatoes, cut into fourths lengthwise. Aim for 1/2″ thick slices. 
  4. Add the tomatoes. Arrange a layer of tomatoes cut side up on top of the garlic cloves. A slight overlap is perfect! Sprinkle the tomatoes with salt. Add a second layer of tomatoes cut side up on top of the first layer of tomatoes and sprinkle with salt. 
  5. Assemble the dish. Pour the olive oil over the entire dish. Make sure to distribute it as evenly as possible. The oil prevents the tomatoes from burning.
  6. Roast the tomatoes. Roast the tomatoes until they start to carmelize around their edges, and are completely softened and shriveled, about 4 1/2 hours. 
  7. Serve. If eating immediately, add parmesan, then pasta to the tomatoes. To store, let the tomatoes come to room temperature before storing in their oil in the refrigerator.



SARDINES. If you plan on using the oven-roasted tomatoes with beef, skip the sardines.


Keywords: slow-roasted tomatoes in olive oil, slow-roasted summer tomatoes, slow-roasted roma tomatoes