Strawberry Rhubarb Pie

Before you start

Rhubarb is the sour backbone of this pie and strawberries bring perfume and sweetness. Together they make one of the juiciest fillings in the pie repertoire: rhubarb is mostly water, and both fruits collapse as they bake. That means a generous amount of cornstarch, a lattice to let steam escape, and a long bake until the juices bubble thickly through the openings.

Use firm, crisp rhubarb stalks with the leaves trimmed away completely; the leaves are not edible. Thin, bright stalks tend to be more tender, while thick green ones can be stringy, so peel any tough outer fibers. Cut the strawberries larger than the rhubarb because they soften faster. A wide-strip lattice, with fewer strips set farther apart, is quicker to weave than a narrow one and gives plenty of venting.

Ingredients

• Crust330 g (2¾ cups minus 1 tbsp) all-purpose flour
• 1 tbsp granulated sugar
• 1 tsp fine salt
• 225 g (1 cup) unsalted butter — very cold, cubed
• 100–130 ml (7–9 tbsp) ice water
• Filling450 g (about 3¾ cups) rhubarb — cut into 1.5 cm (½ in) pieces
• 450 g (about 3 cups) strawberries — hulled, halved or quartered if large
• 200 g (1 cup) granulated sugar
• 40 g (5 tbsp) cornstarch
• 1 tsp finely grated orange zest
• ¼ tsp fine salt
• 1 tsp vanilla extract
• 15 g (1 tbsp) unsalted butter — in small pieces
• Finish2 tbsp heavy cream
• 1 tbsp turbinado sugar

Method

1. Pulse the flour, sugar and salt in a food processor, add the butter, and pulse until the largest pieces are the size of peas. Drizzle in ice water while pulsing in short bursts until the dough begins to clump. Halve, form into two disks, wrap and chill for 1 hour.
2. Roll one disk to a 30 cm (12 in) circle and line the pie plate, leaving a 2 cm overhang. Refrigerate it while you mix the filling.
3. Whisk the sugar, cornstarch, zest and salt in a large bowl. Add the rhubarb, strawberries and vanilla and toss until evenly coated. Spoon the fruit and all of the sugary juices into the crust and dot with butter.
4. Roll the second disk to a 30 cm (12 in) circle and cut six or seven strips about 4 cm (1½ in) wide. Arrange three or four strips across the pie, then weave the rest at right angles, leaving generous gaps between them.
5. Trim the strips to the overhang, fold the bottom crust up over them, and crimp. Brush the lattice with cream and sprinkle with turbinado sugar. Refrigerate for 15 minutes while the oven heats to 220°C (425°F) with a baking sheet on the lowest rack.
6. Bake for 25 minutes. Reduce the heat to 180°C (350°F) and bake 45 to 55 minutes longer, until the lattice is a deep golden brown and the juices bubble slowly through the center gaps.
7. Cool on a wire rack for at least 4 hours before cutting.

Tips for success

• Choose firm, dry strawberries. Very ripe, soft berries add even more juice to an already wet filling.
• Frozen rhubarb works; use it frozen, without thawing, and add 10 minutes to the bake.
• Put a sheet of foil or a pan below the pie. This filling almost always drips somewhere.

Substitutions

Cornstarch

Use 4 tbsp quick-cooking tapioca, ground fine. Let the filling stand 15 minutes before baking so it starts to hydrate.

Orange zest

Lemon zest gives a sharper finish, or use ¼ tsp ground ginger for warmth.

Lattice top

Cover with a crumb topping instead: 100 g flour, 80 g brown sugar, 70 g melted butter and a pinch of salt.

Variations

All-rhubarb

Use 900 g rhubarb, raise the sugar to 250 g, and add 1 extra tbsp cornstarch.

Cardamom strawberry rhubarb

Add ½ tsp ground cardamom to the sugar mixture.

Troubleshooting

Filling poured out like soup

The pie was underbaked or cut warm. Bake until the center bubbles thickly, and cool for at least 4 hours.

Bottom crust is raw

Bake on a preheated sheet on the lowest rack, and use a glass plate so you can see the bottom brown.

Rhubarb pieces are stringy

Thick, mature stalks were used. Peel the tough outer fibers with a vegetable peeler before chopping.

Storage

Store loosely covered at room temperature for 1 day, then refrigerate for up to 3 more days. Baked pie freezes for up to 3 months; reheat thawed slices at 175°C (350°F) for 10 minutes.

Safety notes

Use only rhubarb stalks; discard every part of the leaves. Do not eat raw dough. Contains wheat and milk.