You Say Tomato, I say Roasted Tomato Tart {with caramelized onions}

This savory tart featuring roasted tomatoes is made with an olive oil rosemary crust topped with layers of mascarpone cheese mixed with roasted garlic, roasted tomatoes, and finally, some slowly caramelized onions. Read about the recipe's creation, or scroll down for instructions on making this yourself.

 

Ramona, of The Houndstooth Gourmet, is hosting an event "You say tomato, I say tomahto" devoted to the summer tomato. And how could I resist participating?  I love tomatoes. This summer has been full of new tomato discoveries for me, as I've sampled various heirloom varieties that can't be found at most grocery stores. From my first introduction to the very tasty Mr. Ugly tomatoes to the tiny little yellow tomatoes used as the foundation for this recipe, I've loved them all. Though, if I had to pick, these little yellow ones may be my favorite. They are so sweet and so tangy at the same time. My first introduction to them was from D & S Farms out of southern Maryland. However, these particular beauties pictured were purchased from Anchor Farms at the Sunday DuPont Circle Farmer's Market.

And in honor of this tomato, I created this savory sweet tomato tart. Although, you should feel free to substitute your favorite tomato: big or small, tangy or sweet. In fact, I was compelled to add some sliced tomatoes into my tart, to vary the color and add some interest. I selected a green zebra tomato, and a deep red tomato whose name has now slipped my memory.

After overcoming  my initial fears of making crust with this sweet tart, I just can't seem to get enough of tarts. A whole new world has opened up to me, and I simply had to create a tart with my favorite tomatoes. {It only seemed fair.}

But, this tart shell couldn't be the same one I used for my peach tart. It had to be flaky, that was for sure. But, it needed something different: an herb or a rich flavor.

In the past few months, I've been amazed by La Tartine Gourmande's creativity: she makes seemingly endless varieties of tart shells, using different types of flour and oil. In fact, after my initial tart success I had the courage to try one of her original recipes, using a hazelnut oil for the tart crust. It was a success, and I knew my tart-fearing days were far in the past.

This time, I wanted to make the crust with olive oil- that seemed like the right flavor. I selected a hearty olive oil- a Spanish one with a nice depth of flavor. And to make this crust extra special, I added some freshly minced rosemary leaves.

Of course, the crust was not the only challenge here. I realized that the high water content of the tomatoes could destroy my vision of flaky crust and flavorful filling. How could I get the tart to be delicious without ruining the crispy crust into a soggy tomato mess?

Some research revealed three solutions:

1. Baking the crust for 20 minutes prior to adding any filling.
2. Putting a layer of spreadable cheese on the bottom of the tart.
3. Pre-roasting the tomatoes, to let some of the juices evaporate.

Genius. I felt ready to go, and I just had to find the right combination of cheese, tomato, and additional toppings. It took some time, but I can now say with confidence that this roasted tomato tart topped off with caramelized onions and fresh herbs is something I will make over and over again (until the last summer tomatoes are gone). Simply stated, it was delicious.

Here is my recipe for Roasted Tomato Tart with Caramelized Onions:

It's best to view this tart in components. The crust and topping ingredients are listed separately. Each component is written out into steps to make the process clear and easy for you to follow (or adapt to your own preferences). 

Crust Ingredients

• 1 1/2 Cup all-purpose flour
• dash of garlic powder (optional)
• 1/3 Cup olive oil (preferably one with depth of flavor, like a Spanish olive oil)
• 1/3 Cup ice-cold water
• 1 tsp red wine vinegar
• 1 1/2 tsp salt
• 2 sprigs of rosemary, minced (about 2 TB)

Combine the Ingredients

In a food processor, pulse the dry ingredients (flour, salt, and garlic powder). Stream the olive oil in and continue to pulse. Next, add the ice water and vinegar until well combined. Finally, add the rosemary leaves.

Shape the dough

Remove the dough from the food processor and shape into a ball. Wrap in plastic wrap and shape into a 1/2 inch thick disk. The plastic wrap will assist you in shaping a smooth disk (use the tension of the plastic wrap to your advantage, in other words). Once the disk is the right size, ensure that it is well wrapped and rest in the fridge for one hour.

{So now, let's give some attention to those other ingredients, while we're waiting.}

Topping Ingredients

• One Cup Onion, thinly sliced
• 1 TB butter, more if desired
• 1 tsp fresh basil, thinly sliced
• 1 tsp fresh rosemary, minced
• 2-3 cloves of garlic, skins-on
• 1/2 Cup mascarpone cheese
• 2 tsp crumbled feta cheese {optional}
• 3 Cups baby tomatoes, halved {you can substitute large tomatoes, sliced, or you can mix-and-match, as I did here}
• 1 TB olive oil
• 1 clove garlic, minced

Caramelize the Onions

Heat 1 TB of butter over low heat in a large skillet. Add the onions and slowly caramelize them. {In my kitchen, this means one whole hour of slow cooking in butter.} Add a dash of salt, and stir from time to time. When the onions are nicely browned and perfectly caramelized, turn the burner off. Add the fresh herbs (rosemary and basil). Mix. Set aside.

Make the cheese spread

While those onions are working their magic (I mean, you've got a whole hour to wait for them) throw the 2-3 cloves of garlic, skins-on, into a small skillet on high heat. Toss every few minutes. When the skins have browned on both sides, remove the garlic from the skillet. Once cooled, remove the skins and mash the garlic pulp with a fork. Place in a small bowl.

Add the mascarpone cheese to the bowl and mix thoroughly. If desired, add 2 TB of crumbled feta cheese. Season the mixture with salt and pepper, and place in the refrigerator.

Prepare the tomatoes

Here is where you need to pay attention. Depending on the type of tomato you have, you may want to do this differently. Me- being a complicated girl and all- I chose to use both baby tomatoes and larger sliced tomatoes. You certainly don't need to do this. I just happened to have them on hand and thought they would look good together. Let me start by explaining the baby tomatoes.

1. The baby tomatoes should be halved. Place them in a skillet with 1 TB olive oil and saute over medium heat for about 10 minutes. Add 1 clove of minced garlic and saute for 2 more minutes. Set aside for later.
2. Sliced large tomatoes: I fear that the sliced tomatoes would just fall apart in a sauce pan. I put my sliced tomatoes on a foil lined baking sheet, drizzled them with olive oil, then roasted them in the oven at 250 for about 45 minutes. Mix in some minced garlic after removing them from the oven.

Putting it all together: the fun part

Pre-heat the oven to 400 F. {If you roasted the tomatoes in the oven, they should be out by now, so just increase the temperature.}

1. Form the crust.Remove the crust from the refrigerator. Roll out the dough on a clean, lightly floured surface. Roll it until it will comfortably fit into a 9" pie pan. Place in the pan, and press around the outer edges to create a pretty crinkle. Put the empty crust into the pre-heated oven and bake for 20 minutes until it begins to get slightly golden. Remove, and allow to cool off for 10-15 minutes.

Important: Reduce the oven temperature to 350F.

{Note: at this time, take the cheese spread out of the fridge and allow it to warm up a bit. It will spread more easily.}

2. Let the assembly begin!

Begin by spreading the cheese mixture over the crust.

 

Layer the tomatoes on top of the cheese. {Make them look pretty, if you like.}

 

Put this in the oven and bake for 20 minutes.

Remove from the oven. Add the caramelized onion mixture on top. Return to the oven and bake for 3-5 more minutes.

3. Eat and Enjoy! Let the tart cool off {if you can resist the temptation to immediately dive in}.

The roasted tomato tart is delicious served warm or cold. It would be excellent served alongside a fresh garden salad.

So, you may say tomato or tomahto, but right now I am singing the praises of this roasted tomato tart.