Tarte aux Quetsches (Tarte aux Prunes d'Alsace — Alsatian Plum Tart)

The tarte aux quetsches is the great autumnal tart of Alsace, made each September when the oblong, dark-blue quetsche plums ripen in the orchards along the Rhine plain. In Alsatian households the tart is traditionally eaten for breakfast or as an afternoon snack, never as a formal dessert — the custard base (appareil) sets to a just-set, silky cream that contrasts with the tart, jammy plums. It is humble in preparation and magnificent in result.

Serves: 8

Ingredients

Pastry:

• 200g (1⅔ cups) plain flour
• 100g (7 tbsp) cold unsalted butter, diced
• 1 egg yolk
• 3 tbsp (45ml) cold water
• Pinch of salt

Filling:

• 700g (1.5 lb) quetsche plums (or Italian prune plums), halved and stoned
• 2 eggs
• 100ml (scant ½ cup) crème fraîche
• 2 tbsp (30g) caster sugar
• 1 tsp (5ml) vanilla extract
• 2 tbsp (30g) ground almonds (optional, to absorb juice)
• Icing sugar, to dust

Instructions

1. Make the pastry: rub butter into flour and salt until the mixture resembles coarse breadcrumbs. Add egg yolk and cold water; bring together without overworking. Flatten into a disc, wrap, and refrigerate 30 minutes.
2. Preheat oven to 200°C (390°F). Roll out pastry and line a 26cm (10 in) tart tin with a removable base. Blind bake with baking beans for 15 minutes; remove beans and bake a further 5 minutes until pale gold.
3. Scatter the ground almonds over the base if using — they absorb the plum juices and prevent a soggy bottom.
4. Arrange the plum halves cut-side-up in tight concentric circles, filling the tart completely.
5. Whisk eggs, crème fraîche, sugar, and vanilla together. Pour the custard carefully over the plums — it will barely cover them.
6. Bake at 180°C (350°F) for 30–35 minutes until the custard is set with a slight wobble in the centre and the plum skins have begun to caramelise at the edges.
7. Cool to room temperature, dust with icing sugar, and serve. Best eaten the day it is made.

Cook's Notes: Quetsche plums are sold at farmers' markets in late summer; Italian prune plums (available at most supermarkets) are the best substitute. The tart is intentionally not sweet — Alsatian tradition calls for balance between the tart fruit and the rich custard.