This recipe has been adapted from Alice Water's great cookbook, Chez Panisse Fruit. If you ever find yourself with an excess of fruit on your hands, then this is the book you can rely on to have your solution. Not only that, but the level of detail in her recipes are wonderful - it's a bit like being taught to cook by the kind, patient, wise mother you wish you always had (sorry, Mum). And once you try this pastry, there's no going back to anyone else's: it's rich and buttery, yet mysteriously crunchy, and can be used for every tart under the sun. The amaretti powder is like magic dust, it soaks up the juices and gives this an almondy kick.
For the pastry
150g self-raising flour
½ tsp caster sugar
A good pinch of salt
110g cold, unsalted butter cut into cubes
3 tbsp ice-cold water
For the blood orange syrup
Juice of 2 blood, or regular, oranges
4 tbsp caster sugar
For the amaretti powder
1 ½ tbsp ground amaretti biscuits
1 ½ tbsp caster sugar
1 ½ tbsp ground almonds
1 ½ plain flour
For the galette
700g rhubarb, cut into 5cm lengths
165g golden granulated sugar, plus 1 tbsp
1 tbsp plain flour
2 tbsp melted butter
Make the pastry first. Place the flour, sugar and salt in a food processor and add a third of the butter; pulse until you have breadcrumbs. Add the remaining butter and pulse for only a few moments until the butter is the size of peas (these bits make the pastry flakey).
Transfer to a large bowl, then start dribbling in the water, tossing it and letting it fall through your fingers. Keeping going like this for at least 3 minutes - you want the dough to come together by itself. You will find that it starts to make ropey- bits, keep going until it begins to clump and you have more ropey-bits that dry bits (you may need to add another tablespoon of water. Be patient, you'll thank yourself later! Press into a ball, flatten slightly, then wrap and place in the fridge (or freezer) for at least 30 minutes.
Preheat the oven to 200C/400F/gas 6. Place the blood orange juice and the sugar in a small pan and bring to the boil. Leave to simmer for 5 minutes or so until you have a syrup; keep warm.
Mix the amaretti powder ingredients in a bowl and put to one side.
Roll into a 30cm circle and transfer to a baking sheet lined with baking paper. Sprinkle the dough with the amaretti powder leaving a 3cm un-sprinkled border. Place the rhubarb, sugar and flour in a bowl, toss well so the rhubarb is coated, then pile in a mound over the pastry. Bring up the sides, crimping them a little and folding them over the fruit to create a dam so that the juices don't breach the rim. Brush with the pastry with the melted butter and sprinkle it with the tablespoon of sugar. Place in the oven for 30-35 minutes, rotating it every 10 minutes.
Remove from the oven, brush with the blood orange syrup, and allow to cool slightly before serving.