Lime Curd Tart with Blackberries & Blueberries

Makes 1 tart and serves 8 people
Adapted from Bon Appetit, June 2010

For the lime curd:
3 large eggs
3 large egg yolks
1 cup sugar
¾ cup fresh lime juice (about 8 limes)
6 tablespoons (¾ stick) unsalted butter, cut into 6 pieces

For the Topping:
2 6-ounce containers fresh blackberries
1 6-ounce container fresh blueberries
1 tablespoon blackberry or blueberry jam

For the Crust:
½ cup (1 stick) unsalted butter, room temperature
¼ cup sugar
1 large egg yolk
1 ¼ cups all purpose flour
1 large pinch of salt

For the lime curd: Set fine metal strainer over medium bowl and set aside. Whisk eggs, egg yolks, and sugar in another medium metal or glass bowl to blend. Whisk in lime juice. Set bowl over large saucepan of gently simmering water (do not allow bottom of bowl to touch water). 

Stir constantly with a wooden spoon until the curd thickens and coats the back of the spoon, about 10 minutes. We tried using a thermometer but it interferes with the intuitive process of just knowing when the curd is done. The bubbles will have almost completely disappeared and the color of the curd will have brightened considerably. Remember, humility, patience and confidence.

Immediately pour curd through prepared strainer set over bowl. Add butter to warm strained curd; let stand 1 minute, then whisk until blended and smooth. Press plastic wrap directly onto surface of curd, covering completely. Refrigerate until cold, about 4 hours.

DO AHEAD: Lime curd can be made up to 2 days ahead. Keep chilled.

For the crust:
Using electric mixer, beat butter and sugar in medium bowl until well blended, 1 to 2 minutes.  (Note: Do not use a Kitchen Aid mixer because there is not enough volume to successfully blend in the bowl unless you were to double this tart crust recipe.) Add egg yolk; beat to blend. Add flour and salt and mix on low speed until mixture resembles large, wonky peas. Using hands, knead in bowl just until dough comes together.

Transfer dough to 9-inch-diameter tart pan with removable bottom. Break dough into pieces like tiny bits of Play Dough. Press one hand over the edge of the tart pan and use the other to push the dough evenly up the sides and onto the bottom of the tart pan. Cover and chill 1 hour. 

DO AHEAD: Can be made 1 day ahead. Keep chilled. 

Preheat oven to 350°F. Uncover crust and bake until golden brown, about 35 minutes. Cool completely in pan on rack.

For the topping: 
Remove sides from tart pan and place crust on plate. But note, the tart crust is delicate...handle with care! Spread lime curd evenly in baked crust. Arrange blackberries in 2 concentric circles just inside edge of tart, bottoms up! Not how we did it because it just didn’t look as nice. Mound blueberries in center of tart.

Place jam in small microwave-safe bowl. Heat in microwave until jam is melted, about 15 seconds. Whisk to loosen and blend, adding water by teaspoonfuls if thick. Brush jam over berries.

DO AHEAD: Tart can be made up to 8 hours ahead. Chill uncovered