Leek and Sunchoke Savory Crumble with Greek Yoghurt Sauce

I’ve always thought crumbles were meant to be desserts – as they certainly are – but I had to change my mind when I read on the web about the existence of savory crumbles, that is the salted version of traditional crumble desserts. Of course, why hadn’t I thought of it myself? You just need to add some salt to the topping instead of sugar and substitute the fruit with vegetables (but also meat or fish) and voilà! Les jeux sont fait! Surely, as I am so fond of crumbles, I couldn’t help trying to make my own version of this savory dish which I filled with a combination of leeks and sunchokes. Sunchokes (also called Jerusalem artichokes, sunroot or topinambur) are a novelty to me: I had heard about them but I had never tasted them. So, when I found them at the market, I bought some still uncertain about what to make of them. Sunchokes are vegetable roots, or tubers, similar to potatoes but with a taste closer to artichokes, though more delicate. They match perfectly with leek and, thanks to their dainty texture, to the crispness of a crumble topping.
This crumble is great if served with a yoghurt sauce made with Greek yoghurt and chive.