Nigella's lush, delicious, stunning, enchanting over-writing is bad enough, but Jack's writing is like an incompetent imitation of Nigella's. Not to mention that Nigella's recipes actually work.
And when Nigella starts off a recipe with something like "The idea for this velvety concoction came to me as I was returning home from lunch with some delightful friends who had invited me to their summer home. As I strolled along the peaceful country lanes, the scent of freshly-mown hay, full of promise for the brilliant days yet to come, reminded me of [goes on like this for several paragraphs]" I would be willing to bet that something like this actually happened. Unlike Jack's tiresome variations on the theme of "I'm a wacky smol pixie and this unexpected inspiration just popped into my wildly creative mind".