Pre-heat ofen to 200°C. Rub a cast iron oven dish with 1 tbsp. of canola oil.
Dice the rhubarb and put in a bowl. Mix with 30 g of sugar and 1 tbsp. of canola oil.
In a bowl, mix flour and 100 g of sugar. Add cold margarine in little pieces. Then mix the ingredients with your hands until you have an even crumble. Add rhubarb and 10 g of flaked almonds.
Put the mixure into the oven dish and cover with the rest of the flaked almonds.
Bake for 20 – 25 minutes.