By coincidence I have recently been adding some of the Guardian recipes myself as I love Yotam Ottolenghi's recipes. You can do the same thing using our Bookmarklet - this is explained in Help/How to. When you add recipes you see online, they go into the Library and automatically get added to your Bookshelf.
We would love to add every great recipe in the world to EYB (which is our long-term goal!) but we are spread quite thinly indexing cookbooks, magazines and blogs so we really appreciate it when members add wonderful recipes they see online. We do ask that members follow the EYB indexing guidelines, since we want the quality of data to be maintained, but it is really quite easy to do.