Heat oven to 200C/fan 180C/gas 6.
Roll out the pastry on a lightly floured
surface, then line a 23cm tart tin with
it. Chill in the fridge.
Tip the rhubarb into a roasting tray
with the sugar and juice, then toss
together. Cover with foil, then bake for
30-40 mins. Tip into a sieve over a bowl,
then reserve the syrup. While the rhubarb
is cooking, press a sheet of baking paper
into the tart case, tip in baking beans,
then bake for 20 mins. Remove beans
and paper, then bake for 10 mins more.
Rub the topping ingredients, except the
almonds, together until crumbly. When
the case is cooked, lower oven to 180C/
fan 160C/gas 4. Spoon the rhubarb
evenly over the case and crumble over
the topping. Scatter with almonds, then
bake for 20 mins. Leave the tart until just
warm, then turn out and serve with the
rhubarb syrup and some crème fraîche.