Paris-Brest

Prepare the praline paste. Caramelise 200 g mixed hazelnuts and almonds with 200 g sugar by the dry method (Entry 21), cooking without stirring until the caramel reaches a deep amber. Pour immediately onto a lightly oiled baking sheet and leave to cool completely until brittle and hard. Break into rough pieces and transfer to a food processor. Process for 3–5 minutes without stopping: the mixture will pass through a crumble stage before the nuts release their oils and the mass becomes a smooth, fluid paste. The correctly made paste is deep amber-brown, oily, and flows freely from a spoon — the consistency of tahini.

Prepare the choux pastry to the standard recipe (Entry 18), incorporating one additional egg for a richer, more stable shell. Fit a piping bag with a 1.5 cm plain tip. On a sheet of baking parchment, pipe two concentric rings of approximately 8 cm outer diameter, side by side, to form a double ring. Pipe a third ring directly on top of the seam between the two lower rings to create the preparation's characteristic rounded, domed profile. Scatter flaked almonds evenly over the surface. The piped rings should hold their shape without spreading.

Bake at 200 °C for 15 minutes, then reduce immediately to 170 °C and bake for a further 20 minutes. The high initial heat initiates the puff and sets the outer shell; the reduction to 170 °C allows the interior to continue drying from steam conversion without further surface browning. At the end of the bake, tap the underside of the ring firmly. A clear, hollow resonance indicates the interior structure is fully dry and set. Any dull, dense sound means moisture remains — return to the oven for 5 minutes and test again. This double-temperature bake, and the hollow test that confirms it has worked, is where the Paris-Brest lives or dies: a ring removed too early will collapse when sliced.

Transfer the baked ring to a wire rack and cool completely to room temperature. Do not attempt to slice a warm ring. Using a serrated knife, split the ring horizontally through its equator with a single clean sawing motion. The interior should be hollow, dry, and stable.

Prepare the praline mousseline. The crème pâtissière base and the softened butter must be at the same temperature — room temperature — before they are combined; a temperature differential will cause the mixture to split and appear curdled. Beat the room-temperature pastry cream until smooth, then incorporate the praline paste and beat until fully homogeneous. Add the softened butter in pieces and beat until the cream is light, fluffy, and uniformly coloured. The finished mousseline should be simultaneously intensely nutty, slightly bitter from the caramelisation, and rich. None of these three notes should dominate.

Fit a piping bag with a large star tip. Pipe the praline mousseline in generous rosettes or stars into the base ring, filling it in a continuous crown. Set the top ring in place. Refrigerate until service. Remove from the refrigerator and allow to stand until the internal temperature reaches 14–16 °C — the butter in the mousseline firms under full refrigeration and the cream must be slightly tempered for correct, yielding texture. Dust with icing sugar immediately before service.