Tartelettes mousseline

Yes - the dough already needs at least 1 hour of chilling, so making it a day ahead only helps. Keep the flattened disc wrapped in plastic in the fridge, and let it sit at room temperature for a few minutes before rolling if it has become too firm. The baked, cooled shells can also be made in advance and filled later, which is the easiest way to split the work.

Ground almonds are the closest swap at the same 30 g, and they behave identically in the crumbly rubbing-in step. If you want a nut-free version, replace the hazelnuts with the same weight of flour, which brings the total to 180 g - the shells will be a little plainer in flavour but still bake up golden. Avoid nut flours with added moisture or oil, since the dough relies on cold butter for its texture.

Shrinking usually means the dough was worked too much - the recipe says to knead it quickly, and the second 20-30 minute chill in the mould is there specifically to relax it before it hits the oven. Puffed bases come from skipping the pricking step, which lets steam lift the pastry. If the sides slump, the dough was too warm going in, so chill longer rather than less.

Let them cool completely in the moulds, as the recipe directs - warm shortcrust with butter, sugar and egg yolk is still soft and will crack if you rush it. Use non-stick moulds or grease them well before lining, since this dough has no extra liquid to help it release. Once cool, a gentle tap and a twist should free them.

Keep the empty baked shells in an airtight container at room temperature so they stay crisp; moisture is what turns them soft. Add the strawberry gelée as close to serving as you can, because the fruit purée will slowly soften the pastry from the inside. Once filled, store them in the fridge to keep the gelée set, and expect the base to lose some crunch after the first day.