Shortcrust and choux pastry: crumbly tarts and éclairs that don't collapse

The classic ratio is easy to remember: 1 part sugar, 2 parts butter, 3 parts flour by weight. Plus an egg or yolks to bind and a pinch of salt. From this base you can make almost any sweet shortcrust — for tarts, biscuits, tartlets.

Shortcrust is crumbly because butter coats the flour particles and stops them forming gluten. If the butter melts and you knead for long, gluten develops, the pastry goes tough as leather and shrinks badly in the oven.

Cube the butter and put it in the freezer for 10 minutes. Cut it into the flour with a knife or rub it in with your fingertips to coarse crumbs, add the icing sugar, salt and egg — and bring the dough together in 30 seconds. Visible flecks of butter are normal and even good.

Shape the dough into a flat disc 2–3 cm thick (it chills faster and rolls more easily), wrap it and refrigerate for at least 1 hour, ideally overnight. The flour hydrates evenly and the gluten relaxes — so it shrinks less.

Roll between two sheets of baking paper to 3–4 mm — that way you don't need extra flour, which dries the pastry. If it gets soft and sticky, chill it again for 10 minutes.

Chill the lined tin again for 20–30 minutes before baking. This is your main defence against the sides slumping down.

If the filling isn't baked (cream, fruit, ganache) or it's wet, the case is baked empty in advance. To stop the base puffing up and the sides collapsing, it needs weights.

Choux is the base for éclairs, profiteroles, choux buns and cheesy gougères. Inside it, steam forms during baking, inflating it from within and leaving a hollow for the filling.

Bring the water, milk, butter, salt and sugar to the boil — the butter should be fully melted by the time it boils. Tip in the flour all at once, take off the heat and beat hard with a spatula until it forms a ball.

Return to medium heat and dry the dough for 1–2 minutes, stirring constantly. It's ready when a thin film forms on the bottom of the pan and the dough is smooth and glossy. This drives off excess moisture — and decides whether the éclairs hold their shape.

Add the eggs one at a time, beating thoroughly until smooth each time. The first eggs go in reluctantly and the dough breaks into slippery pieces — keep beating and it comes together.

The exact number depends on how much moisture evaporated, so beat the last egg separately and add it a spoonful at a time. The test: scoop some dough with a spatula and lift it. The right consistency falls slowly and leaves a "beak" on the spatula — a triangle that holds rather than breaking off. Too thick and it tears in lumps; too thin and it spreads.

Pipe onto baking paper or a silicone mat: for éclairs, 10–12 cm lengths with a 12–15 mm star nozzle; for profiteroles, 3–4 cm mounds. Flatten any peaks with a wet finger or they'll burn.

The golden rule: don't open the oven for the first 20 minutes. The pastry is held up only by the steam inside; let cold air in before the walls have set and the éclairs collapse and never rise again.

Fill éclairs only when completely cold: make 2–3 holes underneath with a thin nozzle or skewer and pipe in the filling. Pastry cream, cream-cheese frosting, whipped cream or crème diplomat all work.

Empty shells keep for 2 days in an airtight container or up to a month in the freezer. Refresh them for 5 minutes at 160 °C before filling and they'll be crisp again. Eat filled ones within a day.

Shortcrust dough keeps 3 days in the fridge and up to 3 months in the freezer. Baked unfilled cases keep a week in a tin.