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>