Used by Pizza Hut as nothing more than a garnish in its salad bars in the 1990s, kale has exploded in popularity over the last two decades and has become a go-to nutritional powerhouse ...

Add 50g of the cheddar, the mustard and check the seasoning. Fry the onions in the oil until golden and add the kale. Cook to wilt down for about 2 minutes. Butter a baking dish and put half the ...