When I was a child, kale was an animal feed. Whole fields of it were grown and harvested and then made into silage. It was becuase kale didn't keep well that it wasn't thought fit for human consumption.

Years later, when I had my own garden I grew kale as a winter veg. Treated like spinach - picked, washed and dropped into boiling water, Kale makes a marvellous veg to go with a Sunday Roast.

I have more recently bought it from a supermarket but find it tough and stringy unless the leaves are stripped of their veins - I've never baked it though - can't imagine what a hot oven would do to it.