I made a baked potato with a perfect inside and perfect crisp skin from the books, it involved like 4 steps of how to cook, like bathing them in a specific mixture of salt water, baking for 45 minutes, then running olive oil on the skins, then baking for another 15 minutes.
If they didn’t explain the why in the book, which I guess is the copyrighted part, and what the results are, I never would have tried that recipe.
I’ll have to try your other recommendations now. :)
So a selection of tropes can be copyrightable.