- 125g/4½oz strong white flour, plus extra for dusting
- 125g/4½oz cold unsalted butter
- oil, for frying
- 2 large red onions (or 3 small), thinly sliced
- flaky sea salt, to taste
- 3-4 tbsp dark brown sugar
- 1-2 tsp grainy mustard
- 2 tsp beer vinegar (alternatively use red wine vinegar)
- 1 cucumber
- 1 tsp flaky sea salt
- 1 tbsp caster sugar
- 4 tbsp white wine vinegar
- 1 wheel of goats’ cheese (not too soft)
- few sprigs fresh rosemary, torn into small pieces, to garnish
- For the pastry, put the flour and 5 tablespoons cold water in a freestanding mixer and knead with a dough hook. Alternatively knead by hand until the dough comes together. Add another tablespoon water if necessary. Knead until smooth then set aside to rest.
- Place the butter between two pieces of baking paper. Hit it with a rolling pin to flatten, then roll out into a large square and place in the freezer.
- On a lightly floured work surface, roll out the dough as thin and large as you can. Rest for 5 minutes in the fridge, then roll into a rectangle twice the size of the flattened butter.
- Take the butter out of the paper and put on the dough. Bring the corners of the dough together to encase the butter. Roll out the pastry envelope on a floured surface to make a rectangle that is approximately three times longer than it is wide. Fold one third into the middle and then the other third on top. Seal the edges lightly using a rolling pin. Turn the dough 90 degrees, roll out and fold over again. Place the dough in the fridge while you make the caramelised onions.
- For the caramelised onion, gently fry the onions over a low heat until soft. Add the salt, sugar, mustard and vinegar and cook until very soft. Set aside to cool.
- Remove the pastry from the fridge and roll out and fold as before. Return to the fridge while you make the pickled cucumber.
- For the pickled cucumber, peel half the cucumber and chop into 1cm/½in cubes. Toss these in salt and leave for 20 minutes. Squeeze the cubes and mix with the sugar and vinegar. Chop the remaining cucumber into cubes and set aside.
- Remove the pastry from the fridge and roll out and fold one final time. Chill for 10 minutes.
- Preheat the oven to 180C/160C Fan/Gas 4. Line a large baking tray with baking paper.
- Roll the pastry into a large rectangle and spread with the cooled red onion mixture, reserving a little to serve. Roll up the pastry (like a Swiss roll) starting at a long side and keeping the roll as tight as possible. Slice into 1½–2cm/½–¾in-thick swirls.
- Transfer to the baking tray, leaving room for the swirls to expand a little. Bake for 25–35 minutes until the pastry is risen and golden-brown.
- Meanwhile, slice the goats’ cheese wheel into quarters, then slice the quarters into 5mm-thick slices. Place on a heatproof surface and use a chef’s blowtorch to lightly char them.
- To serve, scoop half a teaspoon of the red onion mixture on top of each swirl. Top with a cube of raw and pickled cucumber, before leaning the goats’ cheese on top. Garnish with small sprigs of rosemary.