Lemon Posset Tart Recipe

Prepare dough

In a bowl or food processor combine flour, salt and powdered sugar. Add cold cubed butter and pulse or cut in with a pastry cutter until mixture resembles coarse crumbs with pea-size butter pieces.

Stir in the cold egg yolk and 1 tablespoon ice water. If dough is dry, add up to 1 more teaspoon ice water, mixing just until dough holds together when pressed. Do not overwork.

Form dough into a disc, wrap in plastic and chill in refrigerator for at least 30 minutes (up to 2 hours).

Blind bake

Preheat oven to 375°F (190°C). Roll chilled dough on a lightly floured surface to fit a 9-inch (23 cm) tart pan with removable bottom. Press dough into pan, trim excess and refrigerate 15 minutes to relax.

Line crust with parchment and fill with pie weights or dried beans. Bake 15 minutes, remove weights and parchment, then bake another 8–10 minutes until edges are golden. Allow crust to cool slightly while preparing filling. Lower oven to 325°F (160°C) for final set if needed.

In a medium heavy-bottomed saucepan combine heavy cream and granulated sugar. Bring to a gentle boil over medium heat, stirring frequently so sugar dissolves and cream does not scorch.

Once it reaches a low rolling boil, reduce heat and simmer gently for 3 minutes while stirring. Remove from heat and cool 1 minute.

Stir in lemon zest and then gradually whisk in the fresh lemon juice. The acid will thicken the cream. Whisk until smooth and evenly thickened.

Pour the warm posset into the pre-baked tart shell. Tap the pan gently to remove air bubbles. Let cool to room temperature, then refrigerate for at least 3 hours or until fully set (overnight is fine). Estimated filling yield fits a 9-inch tart shell.

While the posset chills, prepare the citrus. Peel and segment the blood orange, cara cara (or navel) and lemon using a sharp knife to remove pith and membranes. Place segments in a bowl.

Thinly slice kumquats, remove any seeds and add to the citrus segments. Add 1 tablespoon granulated sugar and the optional 1 teaspoon orange liqueur. Toss gently to macerate for 20–30 minutes. Drain any excess liquid before assembly (reserve a tablespoon of juice if you want to glaze).

Make mascarpone cream: in a chilled bowl whisk mascarpone with cold heavy cream, powdered sugar and vanilla extract until smooth and just spreadable — do not overwhip. You want a thick but soft cream to dollop (about 30–45 seconds by hand).

When posset is fully set, remove tart from refrigerator. Spoon or pipe small dollops of mascarpone cream around the surface, leaving the center and some edges exposed.

Arrange the drained winter citrus segments and kumquat slices artfully over the posset and mascarpone dollops. Use reserved citrus juice or a tiny brush of warmed marmalade (optional) to lightly glaze fruit for shine.

Finish with a few small mint leaves and a light sprinkle of extra lemon zest. Return tart to refrigerator for 15–30 minutes to allow flavors to marry before serving.