Cheesy Caramelized Onion Tart with a Mashed Potato Crust

When I posted the recipe for my Fiesta Potato Pie a little over a year ago, I got a lot of comments about the fact that I used instant mashed potatoes to make the crust. I know, I know, I don’t normally buy instant mashed potatoes either, but I actually developed the recipe for a Hungry Jack instant mashed potato contest! I didn’t win, but still thought the recipe was blog worthy, and I did like the fact that I could easily control the moisture level of the crust by using the potato flakes. Anyway, everyone wanted to know if the crust could be made with real potatoes instead, which I totally understand, so when I was brainstorming ways to use up my 15 pounds of potatoes, I decided to tackle the crust once again!

I’m so glad I did because it turned out beautifully – crusty on the outside and soft and buttery on the inside. This time I filled the unique crust with layers of caramelized onions, shredded gouda cheese, and goat cheese…soooo good! I served the wedges alongside a healthy dose of roasted Brussels sprouts, but a salad would also be lovely. Also, the tart is easier to slice once it’s cooled off a bit.

Cheesy Caramelized Onion Tart with a Mashed Potato Crust
Printable Recipe

Ingredients:
5 tablespoons unsalted butter, divided
2 tablespoons olive oil
4 large yellow onions, sliced (12 cups)
2 garlic cloves, minced
1 teaspoon salt, divided
2 pounds golden potatoes, peeled, and cut into chunks
1/3 cup milk (I used 2%)
2 cups shredded gouda cheese
4 ounces goat cheese

Directions:
Heat 2 tablespoons butter and olive oil over medium low heat in a large nonstick pan. Add onions, cover, and cook 1 hour, stirring every 10 minutes. Remove lid and cook an additional 30 minutes, stirring every 10 minutes, or until caramelized. Add garlic and cook for 1 additional minute; stir in 1/2 teaspoon salt.

Meanwhile, bring a large pot of water to a boil over high heat. Add potato chunks to the pot and boil for 10 to 15 minutes or until fork tender. Drain and mash in a large bowl; stir in milk, remaining 3 tablespoons butter, and remaining 1/2 teaspoon salt.

Heat oven to 350˚F. Press mashed potatoes into a greased 10-inch tart pan with a removable bottom and bake at 350˚F for 40 to 45 minutes or until potato crust is golden brown. Push the center down with the back of a spoon.

Evenly spread half the caramelized onions in the cooked potato pie crust. Evenly crumble goat cheese on top and then half the shredded gouda cheese. Top with remaining caramelized onions and shredded gouda cheese. Bake for 5 minutes at 350°F or until cheese is melted. Let rest for 10 to 15 minutes, use a toothpick to loosen the edges if needed, and remove from tart pan; cut tart into wedges. Makes 8 servings.

Nutrition: 398 calories, 21.0g fat, 6.2g fat, 14.1g protein per serving
Cost: $1.52 per serving