Buy them raw from the supermarket. Just fry then with a small amount of onion. You can do the same with white cabbage, broccoli stalks, cabbage stalks and courgettes. In all cases they should be sliced very thinly and cooked very lightly. We never throw cabbage stalks and broccoli stalks away. With courgettes we give them adusting of flour and fry until lightly brown.