Melted Leek & Jammy Egg Breakfast Tart (Blind-Baked Polenta Crust)

Instructions

1. 1

   In a large bowl, whisk together 1 1/4 cups All-purpose flour, 1/4 cup Fine cornmeal or polenta, and 1/2 tsp Kosher salt. Toss in the cold, cubed butter. Using your fingers, smash the butter pieces into the flour until the mixture looks like wet sand with large, pea-sized chunks of butter remaining. Drizzle in 3 tbsp Ice water one tablespoon at a time, mixing gently until the dough just holds together when squeezed. Why it works: Leaving visible butter creates steam pockets during baking, giving you a lacy, flaky crust.

   10 min

   Tip: If the butter starts getting soft and greasy, put the whole bowl in the fridge for 5 minutes.

2. 2

   Turn the dough out onto a piece of plastic wrap, shape it into a flat disk, wrap tightly, and refrigerate for at least 30 minutes to relax the gluten and chill the butter.

   30 min

   Tip: Fridge is your friend. You can leave this overnight if you are planning ahead.

3. 3

   While the dough chills, melt 2 tbsp Cultured unsalted butter in a wide skillet over medium-low heat. Add 3 whole Large leeks, sliced and the 1/2 tsp Kosher salt. Cook low and slow, stirring occasionally, until they collapse into a sweet, jammy tangle. This takes time, do not rush it. Off heat, stir in 1 tsp Apple cider vinegar and 1 tbsp Fresh thyme leaves. Let it cool.

   25 min

   Tip: Butter is not a garnish here; it is the medium that transforms the leeks from harsh to meltingly soft.

4. 4

   On a lightly floured surface, roll the chilled dough out to an 11-inch circle. Carefully drape it into a 9-inch tart pan with a removable bottom, pressing it gently into the corners without stretching the dough. Trim the overhang. Prick the bottom lightly with a fork.

   10 min

   Tip: Never stretch pastry to fit a pan; it will shrink right back in the oven.

5. 5

   Place the tart pan in the freezer for 15 minutes to firm up the edges. Meanwhile, preheat your oven to 400 degrees Fahrenheit (200 degrees Celsius).

   15 min

   Tip: Freezing the dough right before baking locks the butter in place so the crust holds its shape.

6. 6

   Take a sheet of parchment paper and crumple it into a tight ball, then smooth it back out. Line the frozen tart shell with the crumpled parchment and fill it completely to the brim with pie weights or dried beans. Bake for 20 minutes.

   20 min

   Tip: Crumpling the parchment paper makes it flexible so it sits flush against the dough without tearing it.

7. 7

   Remove the tart from the oven and carefully lift out the parchment and weights. Return the naked crust to the oven for another 10 minutes until the bottom looks dry and the edges are deeply golden. Don't skip this. A soggy bottom ruins a good tart.

   10 min

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

8. 8

   Reduce the oven temperature to 375 degrees Fahrenheit (190 degrees Celsius). Spread the cooled, jammy leeks evenly across the bottom of the hot crust. Using a spoon, make 4 deep divots in the leek mixture. Carefully crack 1 whole Large egg into each divot. Scatter 1/2 cup Gruyère or Comté cheese generously around the eggs, avoiding the yolks.

   5 min

   Tip: Cracking eggs into a small ramekin first guarantees you won't get rogue shells in your beautiful tart.

9. 9

   Bake the tart for 12 to 15 minutes. Watch the visual cues: you want the egg whites to turn completely opaque, but the yolks should still jiggle and wobble when you tap the edge of the pan. Remove from the oven, finish with 1 pinch Flaky sea salt and 1 pinch Black pepper, and serve warm.

   15 min

   Tip: The eggs will continue to cook slightly from the residual heat of the leeks.