However, more than 5.3 million adults would not be able to understand Lawson's instructions as her writing style is too "chatty" and she uses long sentences.
Her books, which include Nigella Bites and How to Eat, often draw on personal observations that detract from the point of the recipe, the report said.
Delia Smith was criticised for having too many different stages to her instructions and using unnecessary adjectives.
She used complex measurements, with some of her recipes requiring the ingredients chopped to the nearest half inch.
Up to half of Smith's recipes and three in seven of Lawson's were too difficult for someone to understand if they did not have GCSE standard reading and numeracy skills.
The two most challenging recipes were Smith's pasta with four cheeses and Lawson's slow roasted aromatic shoulder of pork, according to the research.
Here's Smith's pasta recipe:
I know you can see only three cheeses in the recipe, but there is a hidden one, because Torta Gorgonzola is in fact made from layers of two cheeses, Gorgonzola and mascarpone. Add to that ricotta and some Pecorino and you have a five-star recipe – including the best-quality pasta, of course! If you can't find Torta Gorgonzola, there is a very similar layered cheese called Torta di Dolcelatte, which you could use instead.
8 oz (225 g) dried pasta (penne, for example)
2 oz (50 g) ricotta
3 oz (75 g) Torta Gorgonzola, diced
1 oz (25 g) Pecorino Romano, finely grated, plus a little extra to serve
2 level tablespoons snipped fresh chives
Maldon sea salt
You need to start this by measuring out the cheeses on a plate to have them at the ready, then cook the pasta in plenty of boiling salted water for 1 minute less than the full cooking time (if you're using Martelli or other good-quality pasta this would be 11 minutes) – you need to know your pasta. As soon as it's ready, drain the pasta in a colander and immediately return it to the saucepan so that it still has quite a bit of moisture clinging to it. Now quickly add the chives, ricotta, Torta Gorgonzola and Pecorino, and stir till the cheese begins to melt. Serve it in hot bowls with the extra Pecorino on the table to sprinkle over.
I'm afraid I don't understand how a recipe can get much simpler than this. But for those of you having trouble following it, let me break it down:
- Cut up cheese.
- Boil pasta.
- Drain pasta.
- Stir cheese into pasta.
You'll note that I omitted the chives so as not to confuse anyone. Nigella's complex recipe is here. It is kind of wordy, but that's a literary judgment, not a culinary one.