Oven-Roasted Tomato Sauce

Oven-Roasted Tomato Sauce
Rate it!

oven roasted tomato sauce with pasta
Best and easiest tomato sauce ever!

We’ve known about this recipe for years, and, all that time, we’ve wanted to make it. So, what stopped us? Simply a lack of ingredients. We just didn’t have all the ingredients; specifically, we were lacking fennel. Normally, when we get fennel, we make up a small batch of Fennel Gratin, which we think is nearly the best way to eat fennel, but, last week when we went through the line at the CSA, we selected a nice large fennel with the idea of making Thomas Keller’s Oven-Roasted Tomato Sauce.

Even with that fennel, we’ll be honest and let you know that we still didn’t have all the ingredients: no leeks. Still, we thought that we might as well try it; we’d just use additional onions in place of the leeks. Also, we made half a batch, which was just enough for the two of us, but we’ll list the amounts for a full batch of sauce.

Oven-Roasted Tomato Sauce

Yield: 2 cups tomato sauce

Oven-Roasted Tomato Sauce


  • 2 Tbs canola oil
  • 1 cup white onion, finely diced
  • 1 cup leeks, white part only, finely diced
  • 1 cup fennel, finely diced
  • 4 tsp minced garlic
  • Kosher salt
  • 2 Tbs brown sugar
  • 2 Tbs red wine vinegar
  • 2 (28-32 oz) cans San Marzano tomatoes
  • 1 bay leaf
  • 10 black peppercorns
  • 2 cloves garlic, smashed
  • 3 thyme sprigs
  • Freshly-ground black pepper

Abbreviated Instructions

Preheat oven to 350°F.

In a baking dish, stir together canola oil, onions, leeks, fennel, and garlic. Sprinkle with about 1/4 tsp kosher salt.

Roast vegetables for 45 minutes, or until tender and starting to caramelize.

Add brown sugar and vinegar, return to the oven, and roast an additional 20 minutes, or until all liquid is evaporated.

Meanwhile, drain, seed, and remove tough cores from tomatoes. Reserve liquid for another use. Puree about 1/2 of the tomato pulp in a food processor or blender until smooth. Roughly chop remaining tomato pulp.

In a small piece of muslin or a fine meshed tea-ball, combine bay leaf, peppercorns, smashed garlic, and thyme sprigs. Place in tomato mixture.

Add tomato sauce and pulp to the onion mixture, stirring to incorporate.

Roast sauce for 90 minutes, stirring every 30 minutes.

Remove and discard spices before seasoning with salt and pepper to taste and serving with pasta.


Ingredient discussion:

We happen to love leeks and we almost headed to the store to buy one just for this sauce. Then, we decided that we’d try making this sauce using just onions and see how it turned out, figuring that, if we really liked it, we’d make it again and then we’d use leeks. You can do the same. We do think that you should try to get the fennel, though. It adds a slight sweetness and a faint licorice flavor to the sauce that seems to make a difference. We strongly recommend using San Marzano tomatoes; simply put, they taste better.

Procedure in detail:

Preheat oven to 350°F.

onions and fennel
It’s nice to use the oven for slow-roasting these aromatics, as they’re unlikely to burn or scorch, and you don’t need to stir all the time.

Roast vegetables. Place the oil, onions, leeks, fennel, and garlic in a baking dish and stir to coat with the oil. Sprinkle with about 1/4 teaspoon of kosher salt. Place in the oven and roast about 45 minutes, or until the vegetables are tender and starting to caramelize.

adding brown sugar and vinegar
A bit of vinegar for tartness, and some brown sugar for a hint of sweetness.

Add sugar and vinegar. Stir in the brown sugar and vinegar and return the vegetables to the oven for an additional 20 minutes, or until all the liquid has evaporated.

Half the pulp should be puréed, the other half chopped coarsely.

Prepare tomatoes. With all this roasting going on, you have time to prepare the tomatoes. Place a colander in a large bowl and pour the tomatoes into the colander. Use your hands to break open the tomatoes and remove the seeds and tough cores. Similarly, remove any skin. Let the tomatoes drain for a while. Save the tomato juice that leaks through the colander for another use (we made tomato soup). Purée about half the tomato pulp in either a food processor or blender until smooth; roughly chop the remaining pulp.

making a spice sachet
You can wrap the spices in a piece of muslin and tie it closed, or you can use a fine-meshed tea ball.

Make sachet. Also, while the vegetables are finishing up, make the spice sachet. You can use a piece of butter muslin and some string and tie the spices into a small bag, or, if you have a tea ball, as we have, simply place the spices in that and close it.

making tomato sauce
After the tomatoes go in, the sauce has another 90 minutes of roasting.

Add tomatoes. Add the tomatoes and the spice sachet/tea ball, making sure to push it into the tomato sauce.

Bake. Let the sauce roast for another 90 minutes, stirring every 30. Yes, some of the tomatoes near the edge will blacken, but stir them into the sauce, as they add a delicious flavor. When you drag a spoon through the sauce and no liquid runs back in, the sauce is done.

oven roasted tomato sauce
Finish the sauce by seasoning with salt and pepper.

Season. Remove the spice sachet / tea ball and discard the spices. Taste and add additional salt and pepper as needed.

Serve. We stirred the sauce into some freshly-made pasta for dinner, topping with sautéed mushrooms and just a bit of grated cheese.

This sauce is delicious, but, next time we make it, we’ll be making at least a full batch, possibly even doubling it and freezing some for later. As it was, a half-batch was just enough for the two of eat with pasta. The sauce had a slightly sweet taste, due to the fennel and the long roasting of the tomatoes, but it was balanced by the slightly acid red wine vinegar. Nearly perfect, and so easy! We really want to try it sometime when we have both leeks and fennel. Five stars.

Worth the trouble?

Leave a Reply

Your email address will not be published. Required fields are marked *