Bouchées à la Reine

Soak the sweetbreads in cold salted water for 2 hours, changing the water once, then drain and peel away any visible membrane; set aside.

Halve the onion, carrot and celery. Tie the bouquet garni.

Wipe and thinly slice the mushrooms.

If using a pastry block, roll it out on a lightly floured surface to 5mm thickness. Stamp out 8 circles of 10cm diameter, then use a 7cm cutter pressed only halfway through 4 of the discs to create lids. Chill all pastry pieces on a lined tray.

Rest the pastry in the refrigerator for 30 minutes.

Preheat the oven to 200°C (fan 180°C / gas 6). Brush the pastry cases and lids with beaten egg, taking care not to let it drip down the cut sides. Place on a lined baking sheet.

Bake the pastry for 22–25 minutes until deeply golden and fully puffed. Remove from the oven and immediately use a small knife to lift out and reserve the inner lid, then scrape out any soft doughy interior to create a clean shell. Keep warm.

Meanwhile, place the chicken thighs, sweetbreads, onion, carrot, celery and bouquet garni in a saucepan. Cover with 1.2 litres of cold water, bring slowly to a bare simmer over medium heat, and skim thoroughly. Simmer gently for 25 minutes until the chicken registers 74°C on a meat thermometer at the thickest point.

Remove the chicken and sweetbreads and strain the broth through a fine sieve, reserving 500ml; discard the vegetables.

Once cool enough to handle, pull the chicken meat into small bite-sized pieces, discarding skin and bone. Slice the sweetbreads into 1cm pieces.

In a small sauté pan, melt 10g of the butter over medium-high heat, add the mushrooms and lemon juice, and cook for 4–5 minutes until the liquid has evaporated and the mushrooms are golden. Season lightly and set aside.

Melt the remaining 50g butter in a medium saucepan over medium heat. Add the flour and stir constantly with a wooden spoon for 2 minutes to form a pale roux — it should smell faintly biscuity but not brown.

Remove the roux pan from the heat and ladle in the warm reserved chicken broth gradually, whisking vigorously after each addition until fully smooth.

Return the pan to medium heat and cook, stirring constantly, for 8 minutes until the velouté is thick enough to coat the back of a spoon.

In a small bowl, whisk together the double cream and egg yolks. Remove the velouté from the heat and stir in the cream mixture in a slow stream, then return briefly to a very low heat for 2 minutes, stirring — do not allow to boil or the yolks will curdle.

Fold in the chicken, sweetbreads and mushrooms. Adjust seasoning with salt, white pepper and nutmeg.

Spoon the hot filling generously into the warm pastry cases, mounding it slightly above the rim. Rest the pastry lids at an angle on top and scatter with chopped parsley. Serve immediately.