Tarte au Fromage Blanc

Ingredients

• For the pâte sucrée or pâte brisée base
• 1 tart shell, pre-baked (24–26 cm diameter, 4–5 cm deep), blind-baked 15 minutes at 190°C
• For the filling
• 750 g fromage blanc, 40% fat; drained in a sieve for 2 hours to remove excess whey
• 150 g caster sugar
• 4 eggs, separated
• 50 g cornstarch or plain flour
• 1 lemon, zest and juice
• 1 tsp vanilla extract
• 1 pinch salt
• To serve
• 20 g powdered sugar, for dusting
• 200 g mirabelle compote, optional; canonical late-summer pairing

Method

1. 1
   At least two hours before baking, turn the fromage blanc into a fine-mesh sieve set over a bowl. Leave to drain at room temperature until no further whey drips; the mass should feel dense and hold its shape when pressed. Weigh 750 g of drained curd before proceeding.
2. 2
   Blind-bake the lined tart shell at 190 °C for 15 minutes. Remove the baking weights; the pastry should be dry to the touch at the base, pale gold at the rim. Set aside to cool slightly while the filling is prepared.
3. 3
   Whisk the egg yolks with the sugar until the mixture is thick, pale, and falls from the whisk in a slow, continuous ribbon.
4. 4
   Fold the drained fromage blanc into the yolk–sugar base until fully combined, then fold in the cornstarch, lemon zest, lemon juice, and vanilla extract. The batter should be smooth and hold a faint trail on the surface.
5. 5
   In a clean bowl, beat the egg whites with the pinch of salt to firm peaks — the whites should stand upright when the whisk is lifted, with no slump. This is where the dish lives or dies: insufficiently beaten whites will collapse into the batter and produce the dense, heavy filling the Alsatian tarte is defined against; overbeaten whites will streak rather than merge.
6. 6
   Fold the beaten whites into the fromage blanc base in two additions, using a large spatula and a deliberate cutting motion to preserve volume. Stop as soon as no white streaks remain; the batter should look light, airy, and slightly risen in the bowl.
7. 7
   Pour the filling into the pre-baked tart shell and transfer immediately to an oven preheated to 170 °C. Bake for 40–50 minutes. The tart is ready when the edges are fully set and the centre, when the tin is gently tapped, wobbles in a single slow, cohesive movement — not a liquid ripple. It will firm further as it cools.
8. 8
   Turn off the oven. Leave the tart inside with the door ajar for 30 minutes. Transfer to a wire rack and cool to room temperature; the surface should remain uncracked and faintly golden. Refrigerate overnight for the optimal texture, and bring to room temperature for 30 minutes before serving.
9. 9
   Dust with powdered sugar immediately before serving. Accompany with mirabelle compote if in season. The first clean slice, holding its shape without slumping, confirms the filling has set correctly.