Peel and dice the butternut and parsnip. Also peel the onion and mix together with the garlic. Cut the leek into thin slices
Dice the chorizo into bit size pieces
Heat the oil in a wok. Fry the onion on medium heat for 5 minutes; Add the leek, chorizo and cook for five more minutes. Now add the parsnip and butternut. Season with some pepper. Add a little bit of water and cook for 20-30 minutes.
For the crumble, put the flour, Parmesan, oat and pine nuts in a bowl. Add the diced butter. Knead with the tip of your fingers and until dough is crumbly.
Preheat oven on 400F
Put all the vegetables in an oven dish and cover with crumble. Bake in the oven for 20 minutes until top is golden.