I believe that all you need to do here is to just specify the variable, i.e.: [% foo %].
After all, from TT’s point of view, you aren’t “INCLUDEing” another template-file. You’re just inserting the contents of a Perl variable (or function, what have you) into the output stream. The fact that this variable happens to contain HTML is of no interest to TT, and the web-browser will not be able to tell the difference.
The only thing that you have to be aware of (and please note that I have not worked with Catalyst in quite some time) is how to present the variable to TT in such a way that it, one way or another, represents a value withdrawn from the “stash.”
Bear in mind that a TT “variable” can correspond to a Perl function (a “closure,” to use the fancy-pants computer science term), such that when TT encounters it, TT will see that it corrsponds to a code-ref, and therefore will call that function and use its result. Very handy sometimes. The concept might be useful here, or, as the case may be, it might be overkill, but it’s a very good feature of TT to be aware of.
