• 1 puff pastry sheet (half of a 17.3-ounce package or chef Cathal's recipe)
• 1 egg white , lightly beaten
• 1/2 cup huckleberry jam (or other jam)
• 12 Tbsp. (1 1/2 sticks) unsalted butter
• 1/2 cup plus 2 Tbsp. sugar
• 4 large eggs
• 1/2 cup flour
• 1/2 tsp. salt
• Whipped cream , for serving
• Fresh berries , for serving

Preheat oven to 375°. Roll out puff pastry on a floured surface to 1/4-inch thick. Grease an 8-inch tart pan, then line with pastry, trimming excess. Prick base all over with a fork. Chill 15 minutes.

Line inside of pastry with parchment paper, and fill with pie weights. Cook 15 minutes, or until pastry is golden. Remove weights and parchment; lightly brush pastry with egg white, and bake 5 minutes more. Spread jam on bottom of tart and cool about 20 minutes.

Lower heat to 325°. In a medium bowl using an electric mixer, cream butter and sugar until pale. Beat in eggs, one at a time, then gently fold in flour and salt.

Pour mixture into tart. Bake until golden and set, about 40 minutes. Cool completely on a rack. Serve with whipped cream and berries.

Chef Armstrong recommends pairing this dish with a Sullin.