Southern Heirloom Tomato & Caramelized Vidalia Tart

Instructions

1. 1

   Place 2 lbs mixed heirloom tomatoes in a single layer on a wire rack set over a baking sheet. Sprinkle evenly with 1 tsp kosher salt. Let them sit to draw out their excess moisture. This is crucial for a crisp pastry.

   10 min

   Tip: Don't rush the salting process. Heirloom tomatoes hold a ton of water, and pulling it out is the secret to a tart that slices beautifully.

2. 2

   In a large bowl, whisk together 1 1/4 cups all-purpose flour, 1/2 tsp kosher salt, and 1 tsp freshly cracked black pepper. Cut in 1/2 cup unsalted butter using a pastry blender or your fingers until the mixture resembles coarse meal. Drizzle in 1/4 cup cold buttermilk and gently bring the dough together.

   10 min

   Tip: Keep the butter as cold as possible. If it starts getting warm, throw the bowl in the freezer for 5 minutes.

3. 3

   Turn the dough out onto a floured surface, form it into a disk, and roll it out into an 11-inch circle. Carefully transfer the dough to a 9-inch tart pan with a removable bottom, pressing it gently into the edges. Trim the excess, then place the tart pan in the freezer to chill.

   10 min

   Tip: Freezing the dough relaxes the gluten and sets the butter, ensuring the crust won't shrink during the blind bake.

4. 4

   While the dough chills, heat 1 tbsp olive oil in a skillet over medium heat. Add 1 large Vidalia onion and 1 tsp fresh thyme leaves. Sauté until the onions are deeply caramelized and jammy. Remove from heat and stir in 1 tsp fish sauce.

   20 min

   Tip: The fish sauce won't taste fishy at all—it just adds an incredible savory depth that anchors the sweetness of the onion.

5. 5

   Preheat your oven to 400°F (200°C). In a small bowl, mix together 1 cup aged sharp cheddar cheese and 1/4 cup Duke's mayonnaise until it forms a thick paste.

   5 min

   Tip: We're using much less mayo than a traditional tomato pie to keep the tart light and elegant.

6. 6

   Remove the chilled tart shell from the freezer. Line it tightly with parchment paper and fill it to the brim with pie weights or dried beans. Bake for 20 minutes.

   20 min

   Tip: This technique, called blind baking, is non-negotiable for a crisp bottom crust when dealing with juicy summer produce.

7. 7

   Carefully remove the parchment and pie weights. Return the tart shell to the oven for 5 more minutes until the bottom looks dry and lightly golden. Remove from the oven and reduce the oven temperature to 375°F (190°C).

   5 min

   Tip: If the bottom puffs up slightly, gently press it down with the back of a spoon.

8. 8

   Thoroughly pat the salted tomatoes dry with paper towels. Brush the warm crust with 1 tbsp Dijon mustard. Spread the caramelized onions in an even layer over the bottom. Drop small spoonfuls of the cheddar-mayo mixture over the onions, then arrange the dried tomatoes on top in an overlapping circular pattern.

   10 min

   Tip: Patting the tomatoes dry is your final insurance policy against a soggy bottom.

9. 9

   Bake the assembled tart at 375°F for 35 minutes, or until the tomatoes are slightly shriveled and roasted, and the visible cheese is bubbling and golden brown.

   35 min

   Tip: Let the oven do its work; the tomatoes will concentrate in flavor and become intensely sweet.

10. 10

    Remove the tart from the oven and allow it to cool in the pan on a wire rack for at least 15 minutes before removing the tart ring. Garnish with 1/4 cup fresh basil leaves just before slicing.

    15 min

    Tip: Don't cut it while it's piping hot! Letting it rest allows the juices to settle so you get clean, beautiful slices.