To give a little startup help underneath there is a xquery which you can run in kernow that returns all the ingrediences which consist of other ingrediences
declare namespace rcp="http://www.brics.dk/ixwt/recipes"; 
declare variable $recipies := doc('http://www.brics.dk/ixwt/examples/recipes.xml')//rcp:recipe;
<result> {
for $i in $recipies
let $ing := $i/rcp:ingredient[./text()]
return $ing/@name/string() } </result>