Did everything as described, it turns out this result
1) Why recipeInstruction empty?
HTML like this: collabshot.com/show/GLDWx5
that is, the text is precisely there, in the tags
2) Where did the "mandatory" field description? in the specification it is not.
it better: awesomescreenshot.com/09b37y4w30
but the result aimed at Yandex, so the question arises