My mum found this recipe in some magazine a while back but it's definitely worth a try since it's so crunchy and delicious.
Ingredients
500 g rhubarb
100 ml caster sugar
1 tbsp potato starch (flour)
300 ml flour
2 tsp baking powder
200 ml caster sugar
1-2 tbsp lemon juice
grated zest of 1/4 lemon
1 egg
50 g butter + butter for greasing the dish
Preheat the oven to 225 degrees.
Peel and chop the rhubarb stalks in about 1 cm big pieces. Put them in a bowl together with the 100 ml sugar and potato starch. Mix together and let it sit for a while.
For the dough; mix together flour, baking powder, sugar, lemon juice, lemon zest and egg in a bowl and work together to form a crumbly dough. Put half of the dough in a greased pie dish (approximately 24 cm diameter), add the rhubarb pieces on top and finish with the rest of the pie crumble.
Put the pie dish in the oven for about 10 minutes. Take it out and shave the butter on the top. Then put it back in the oven for another 10 minutes until it has a nice colour. Serve with some lightly whipped cream flavoured with some vanilla sugar.