This is another of those “to-die-for” tarts I made a couple of weeks ago. Caramelized Onions, slices of zucchini, tomatoes and mushrooms filled my Homemade Pie Crust-lined tart pan. The veggies were seasoned with lots of delicious Italian seasonings, and smothered in four different hard cheeses: Asiago, Parmesan, Fontina, and Pecorino Romano. Yum, yum, good was the reaction from our guests when I served this wonderful tart. While this scrumptious tart cannot be classified with a “quick and easy ” description since it is a lot more involved and time-consuming, it can certainly be classified as one of the BEST veggie tarts you’ll ever eat! Those of you still reaping veggies like tomatoes, onions, or zucchini from your garden will love being able to use them in this tasty recipe.
This lovely tart can be made as a side dish or as a main dish–particularly on Meatless Mondays. It’s very hearty, filling and satisfying, plus it just pops with flavor on those taste buds. It’s not excessively high in calories and is certainly a lot healthier than tarts or pies made with canned soups, gravy mix, ranch dressing mix and other ingredients with a lot of MSG, preservatives, and fillers. I know those foods have their place in cooking but I try to limit my use of them as much as possible. When I do, I find I don’t crave food all the time or have such an enormous appetite as when I eat something with MSG, sugar, or high fructose corn syrup.
Making up a Caramelized Onion, Zucchini, Tomato and Mushroom Tart is a great way to use up garden produce, and if you don’t have time to make your own Homemade Pie Crust, than simply use a store bought crust. Here are a few recommendations when making this tart: First, plan plenty of time because it will take about an hour to caramelize the onions fully and you need to lay the tomatoes and zucchini out on the counter to drain for at least an hour as well. This will help prevent too much liquid in the pie which causes a soggy crust. Second, don’t place any of the filling in the pie crust until it is all ready to go (including having the oven at the preheated temperature). Leaving any kind of filling ingredients in a tart or pie shell and not baking immediately will cause a soggy crust. Third, while I provide some detail for caramelizing the onions, if you need more explicit directions on how to do this than check out this post. Fourth, don’t make the pie crust for the tart until after the onions are caramelized and the tomatoes and zucchini have drained. Otherwise, the pie crust will dry out and get brittle.
While Caramelized Onion, Zucchini, Tomato and Mushroom Tart is my own concoction, I am indebted to Milk Glass Kitchen’s Caramelized Onion and Heirloom Tomato Tart and her source, Ina Garten’s Tomato and Goat Cheese Tart, for some of the original directions in both this recipe and the Caramelized Onion and Tomato Tart Au Gratin recipe already posted. Their ideas for caramelizing the onions and draining or dehydrating the vegetables before making this tart were extremely helpful and should be acknowledged even if I changed the tart up beyond recognition. I am very grateful that they shared their recipes, directions, and helpful tidbits so freely with others. Special thanks also to Elise Bauer from Simply Recipes and her wonderfully detailed instructions on How To Caramelize Onions as well. It is chefs like these, who help the rest of us achieve greater feats in the kitchen!
If you’re looking for a marvelous tart recipe with radically amazing taste than please consider making up a Caramelized Onion, Zucchini, Tomato and Mushroom Tart sometime soon. Neither you, nor your family (or guests) will be disappointed with this sensational tart. The flavors are delectable and you will berate yourself for making ONLY one! Usually I send a lot of leftovers home with our guests, but I was rather selfish with this tart and kept all the leftovers for my lunch the next day! This tasty tart even reheats well. You can also freeze the tart before or after baking and bake again (which is what I did for the third kind of tarts I made–which will be posted at a later time)!
Caramelized Onion, Zucchini, Tomato and Mushroom Tart is a sumptuous main dish recipe for Meatless Mondays.
Here’s a serving of this delicious tart.
This special tart is filled with four different cheeses.
This side view shows the texture of the caramelized onions on the bottom, a cheese layer, tomatoes, zucchini, mushrooms and more cheese on top!
Here’s an inside view of the tart.
I sprinkled pecorino romano cheese and several different herbs on top of the veggies.
Here’s a close up so you can see the texture of Caramelized Onion, Zucchini, Tomato and Mushroom Tart.
Here’s what I did.
Fit Homemade Pie Crust or store bought pie crust in tart dish.
Trim off edges. I highly recommend you don’t make the crust until the onions are caramelized and the tomatoes and zucchini have drained so the crust doesn’t dry out.
Slice tomatoes and set out on paper towels to drain. Sprinkle very generously with salt. The tomatoes need to drain at least an hour. Mine were actually on the counter about three hours before I used them.
Slice zucchini and lay out on paper towels to drain. Sprinkle the zucchini also very generously with salt. The zucchini needs to drain at least an hour. Mine was actually on the counter about three hours before I used it.
Add a little olive oil to your large cast-iron skillet and begin sauteing the onions over a medium heat.
Continue cooking and turning occasionally for about a half hour. Be careful that the heat is not so hot that the onions scorch, or that you turn the onions so frequently that they don’t brown and caramelize.
Season onions with salt, pepper, thyme and white wine vinegar.
I’ve added the seasonings and here I’m adding the vinegar.
Keep sauteing the onions until they caramelize. You may have to add a little water to keep them from sticking too much to the pan.
Mine took about an hour and a half to get to this point. They should cook down in 45 minutes. I probably had my heat too low and turned the onions too frequently because I was afraid they’d scorch.
Once the onions are caramelized and the tomatoes and zucchini have drained it’s time to layer your tart. Don’t begin until everything is in place otherwise your crust will become soggy. Place the caramelized onions in the tart dish.
These are the four cheeses I used in this tart.
Sprinkle parmesan cheese over top of the onions.
Add asiago cheese.
Add fontina cheese.
Add a layer of zucchini.
Add a layer of tomatoes overlapping each other and then add a small layer of zucchini slices in the middle of the tart in a ring shape.
Add sliced mushrooms around the edge. Sprinkle with seasonings and pecorino romano cheese. Bake at 350 about 20-25 minutes or until done.
Here the tart is just out of the oven. Serve immediately.
To serve the tart: slice in eighths.
Caramelized Onion, Zucchini, Tomato and Mushroom Tart is a wonderful comfort food. The savory flavors of the cheese and herbs with the added sweetness of caramelized onions are amazing.
Using four different cheeses adds depth of flavor.
Making this tart is a great way to use up garden produce like tomatoes, zucchini, or onions.
Even the children we served this to enjoyed this delicious, mouthwatering tart.
Here’s another close up so you can see the pecorino romano cheese on top.
Here’s the recipe.
CARAMELIZED ONION, ZUCCHINI, TOMATO AND MUSHROOM TART
1 whopper onion (1-lb. onion or two large onions)
½ tsp. kosher salt
¼ tsp. pepper
½ tsp. thyme
3 tbsp. white wine vinegar
1 medium zucchini sliced
3 large tomatoes, sliced
4-oz. sliced mushroom, halves
½ tsp. basil
½ tsp. oregano
½ tsp. rubbed sage leaves
½ tsp. crushed rosemary
½ cup finely grated pecorino romano cheese
½ cup parmesan cheese
½ cup fontina cheese
½ cup Asiago cheese
Slice tomatoes and zucchini and lay on paper towels on countertop. Sprinkle very generously with salt and allow to drain a minimum of one hour. Meanwhile, heat olive oil in a large cast-iron skillet to low to medium heat. Slice onions and add to skillet. Sauté about 30 minutes turning occasionally so onions don’t burn. Add salt, pepper, thyme and white wine vinegar. Continue cooking and turning another 15-30 minutes until onions turn a dark amber color. You may have to add a little water so the onions don’t stick. Use a heavy metal spatula to remove any onions stuck on the bottom of the pan. Set aside. Prepare your pastry and gently fit it into a 10-inch torte pan. Once onions, tomatoes and everything else is ready, place caramelized onions in bottom of torte pan. Then sprinkle with Parmesan, Fontina and Asiago cheeses. Layer zucchini in torte pan but do not overlap edges. Add tomatoes but overlap them using all. Place the remaining zucchini slices in the center of the torte pan overlapping in a circle. Place mushroom halves around the outside border of the torte pan. Sprinkle with basil, oregano, rubbed sage leaves, and rosemary. Then sprinkle the finely grated pecorino romano cheese over top. Bake at 350° for about 20-25 minutes until crust is done and veggies are cooked fork-tender. Serves 8.
Doesn’t Caramelized Onion, Zucchini, Tomato and Mushroom Tart look spectacular?
We loved the sensational taste of this tart recipe.
Take my advice and make two of these delicious tarts when you’re making them. Everyone will want a second slice!
You can always add more layers or more mushrooms if you desire.
I’m ready for a bite of this veggie pie right now!
Join me for supper!