This tart turned out absolutely A-M-A-Z-I-N-G!!! Lots of caramelized onions lay in one of my homemade pie crusts topped with four cheeses, a layer of sliced tomatoes, several delicious herbs, with more cheese on top. Spectacular is about the only word worthy of this fabulous tomato tart recipe. My mouth is watering just thinking about the awesome texture and flavors of this tomato and onion pie.
For those of you who follow me on Pinterest, you will remember that last week I probably pinned 20 or 30 different tomato tart recipes as I was trying to find one that I really wanted to try. I began seeing all these wonderful looking pictures of tomato tarts online and finally landed at this recipe, based on Ina Garten’s Tomato and Goat Cheese Tart. I liked several things from this recipe but even though I had goat cheese on hand I didn’t want to make this particular tart with goat cheese or do the mayonnaise-dijon mustard combo I had seen in other recipes.
So while I took the idea for the caramelized onions from these two recipes, and the idea of setting the tomatoes out on the counter to dehydrate for an hour from Milk Glass Kitchen’s rendition, and even used some of their seasonings, I departed completely from some of their other ingredients and instead I used Asiago, Parmesan, and Fontina cheeses on the tart underneath the tomatoes and Pecorino Romano cheese on the top after I’d seasoned them. All I can say about this tart is that the taste was fantastic.
It does take a few minutes to whip up a homemade pie crust, (for me, it takes about 5 to 10 minutes depending on how many crusts I’m making at one time), but you can substitute store bought pie crust if you have never made one before or don’t have time. The tomatoes need to be sliced, salted and set out on paper towels for at least an hour to drain. This helped the pie not become soupy. The longest thing for me to do was caramelizing the onions. It seemed to take FOREVER! To my chagrin I’ve never caramelized onions before so I was afraid to have my heat too high and scorch them. As a result they probably took about one and a half hours before it was all said and done! Perhaps because I was doing two batches, but everyone else says you can do it in about 45 minutes. Be prepared for them to take a while to cook. This site was the most helpful in learning how to caramelize onions for the first time.
Here are a few of my recommendations: First, after you make the pie crust, set it aside and don’t put ANYTHING into the pie shell until you have all the components ready. If you allow the onions, cheeses, or tomatoes to sit in the pie for any length of time before baking, you will end up with a soggy crust. (This is the same for making fruit pies. Don’t allow the fruit mixture to sit in an unbaked pie shell for more than a minute or two before tossing the pie into the oven if you don’t want a soggy crust). Truthfully, you are better off getting everything else ready first, THEN make your pie crust. That way your pie crust won’t dry out while you’re getting everything else ready.
Second, caramelize the onions when you have plenty of time. You can even do these the night before and stir occasionally while you’re watching TV. Then store them in a refrigerator until ready to use. At your earliest opportunity the day you want to make the tart, slice the tomatoes and set them out on paper towels to drain being sure to salt them generously. It doesn’t matter if they set out a few hours before you have time to get around to them, just get them draining on the counter until you’re really ready to make the recipe. You will be amazed at how much liquid will drain from the tomatoes. I made two different types of tarts and then about 18 or 20 miniature tarts at the same time so I had tomatoes, heirloom tomatoes, grape tomatoes and zucchini all sitting out at the same time. There was probably a cup of liquid run-off from all of the stuff I did!
Finally, when I was ready to assemble the tart, I laid the caramelized onions in the bottom of the crust, sprinkled three of the four cheeses over top of the onions, placed tomatoes over top of the cheeses in overlapping fashion, sprinkled the tomatoes with all the seasonings, and then topped everything with the pecorino romano cheese. As soon as I finished assembling all the ingredients, the tart/pie went into the oven. It goes without saying that you need to have a preheated oven!
If you’re looking for a great new way to use up garden tomatoes or onions, than by all means consider this recipe. Just be prepared for the fact that it may take a few hours to get it all done from start to finish. Even still, you will sink your teeth into one of the most delicious, tantalizing tomato tarts you have EVER tasted. Caramelized Onion and Tomato Tart Au Gratin is the real deal! Oh, my, it’s one of those recipes I think I could eat almost every day! This healthy, low calorie, and tasty tart is excellent served as a side dish, but I also ate it as a main dish. Add a salad or bread, and it is yum, yum delicious.
Caramelized Onion and Tomato Tart Au Gratin is one of the BEST tasting tarts you will ever eat.
This scrumptious tart recipe is sweetened a little by the caramelized onions.
The savory blend of cheeses adds depth to a very rich tasting tomato tart.
Here’s a side view so you can see the texture of this amazing tart.
Caramelized Onion and Tomato Tart Au Gratin is a bit of work, but it was SO worth it in the end!
I served this first-try recipe to company and everyone loved it.
Here’s another close up so you can see the little bits of pecorino romano cheese on top.
Okay, it’s time to slice off a piece for yourself! Here’s what I did.
I whipped up a batch of my Homemade Pie Crust recipe. I started out with 3 cups of flour (honestly, I don’t measure much, I go by texture, look, and feel), and that was enough crust to make 2 large torte pans like this, plus about 15-18 small miniature tart dishes.
I cut off the edge (and used all the leftover pieces for the small miniature tart dishes).
This is what the tart dish looks like after fitting it with crust. This tart dish is not as deep as a normal pie plate. Honestly, it is better for you to make up all the other ingredients and have them ready before making your pie crust. You don’t want your pie crust sitting out too long and getting dried out.
I had whopper-sized onions. This picture really doesn’t do them justice. They must have weighed between one-two pounds each! Slice onions and separate into rings.
Place some olive oil in a cast-iron skillet over medium heat and begin sauteing onions.
Slice down tomatoes and set on paper towels. Generously sprinkle with salt. Allow the tomatoes to drain (dehydrate) at least one hour. Mine were laying out about three hours before I got around to them.
Continue sauteing onions. After about a half hour, add salt, pepper, thyme, and white wine vinegar or white wine.
Here I’m adding the white white vinegar.
It took forever for these to cook. I’m not sure if my heat was too low or I was stirring them too frequently.
This was after about an hour.
This was closer to an hour and a half! They still aren’t as caramelized as they should be, but by this point I couldn’t wait any longer and had to get going on the recipe.
These are the four different types of cheeses I used. I didn’t want to use the strongly flavored goat cheese with this recipe.
Spread caramelized onions over the bottom of your pastry shell.
Sprinkle parmesan cheese over top.
Now sprinkle with Asiago cheese.
Now sprinkle with Fontina cheese.
Add your tomatoes in an overlapping fashion to completely cover the tart dish.
Season with rubbed (not ground) sage, rosemary, oregano and basil. I grabbed two or three pinches and crushed the leaves in between my thumb and fingers a little bit before adding on top. It was probably at least 1/2 tsp. of each seasoning. Use more if you like a lot of seasoning on your tomatoes!
Now all the seasonings have been added on top of the tomatoes.
Sprinkle with finely grated pecorino romano cheese and bake at 350 about 20-30 minutes until tomatoes are tender and crust is lightly browned.
Here’s what my tart looked like just out of the oven.
Caramelized onions and tomatoes are a wonderful combination. Then when you add all the cheese and seasonings – WOW! This recipe just pops with flavor.
Here’s a serving of Caramelized Onion and Tomato Tart Au Gratin.
This close up shows the finely grated pecorino romano cheese on top.
Even the kids enjoyed this tasty tomato tart recipe.
You can also refrigerate or freeze the tart and reheat it for later.
This side view shows the caramelized onions on the bottom of the pie.
This spectacular recipe is a great one to use up garden veggies like tomatoes or onions. Here’s the recipe.
CARMELIZED ONION AND TOMATO TART AU GRATIN
(Recipe adapted from Milk Glass Kitchen, source: Ina Garten) 1 whopper-sized onion, sliced and separated into rings (about 1-lb. or two large onions) 2 tbsp. olive oil 3 tbsp. white wine vinegar ½ tsp. thyme ½ tsp. kosher salt ¼ tsp. pepper 3 large tomatoes, sliced ½ cup shredded parmesan cheese ½ cup shredded Asiago cheese ½ cup shredded fontina cheese ¼ to ½ cup finely grated pecorino romano cheese ½ tsp. basil ½ tsp. oregano ½ tsp. rosemary, crushed ½ tsp. rubbed sage leaves recipe for single crust plain pastry Slice tomatoes and lay out on paper towels. Sprinkle very generously with salt and allow to set out on counter and drain for at least one hour. Add olive oil to a large cast-iron skillet and heat over low to medium heat. Add onions and cook about 30 minutes turning occasionally so onions don’t burn. Add thyme, salt, pepper, and white wine vinegar. Continue cooking another 15-30 minutes or however long it takes to caramelize the onions. You may need to add a little water so the onions don’t stick too much. Use a heavy-duty metal spatula to scrape onions from pan if necessary. Prepare pie crust and fit into a large 10-inch tart pan. When all the other ingredients are ready, layer the caramelized onions on the bottom of the tart pan. Sprinkle Parmesan, Asiago and Fontina cheeses over top of the onions. Add tomato slices overlapping the edges. Sprinkle tomatoes with basil, oregano, rosemary, and rubbed sage leaves. Then sprinkle pecorino romano cheese over top of all. Bake at 350 for about 20-30 minutes until tomatoes are tender and crust is done. Serves 8.
Doesn’t Caramelized Onion and Tomato Tart Au Gratin look delicious?
This fantastic tart is sure to tantalize your taste buds!
You know a recipe’s a hit when little children love it!
I’m starting to drool over those caramelized onions. They added so much flavor to the recipe.
Our family and company enjoyed this version of Caramelized Onion and Tomato Tart Au Gratin and believe yours will too!
Here’s your sample!
Because I didn’t add the ingredients to the pie crust until right before baking the crust came out wonderfully. No soggy crust!
Inhale, exhale, now drool!