Re: I want my users to submit variants of wiki-articles, how do I do this?
Another way (more robust for new users not adding the tags or setting the right category) is to use a wiki structure, which will show your users the field to create a new page (sister to Lasagna, or child) to create new pages to that structure. Ideally, you would want them to create child pages (as variants of Lasagna recipe). In Lasagna page, you add the code
{toc}
and your users will see there the table of contents of the child pages to that one (the variants of Lasagna).
And if they want to add some new recipees, Macaroni Carbonara (or whatever), they would add sister pages to Lasagna (not checking the "child" option), etc.
See the documentation about Structures
HTH
P.S. As far as I remember, you can also combine categories with structures (force categorization of pages for users, or -reset a whole structure tree to be categorized to X, etc)