[lucb1e]

I read it as having meaning #2 but it depends on the intonation and context. If you emphasize fried then it's #3. If we're talking about having fried onions and not in your kitchen I'd probably assume #4.

As for which ones work in Dutch, all of them.

[tripzilch]

Number 4 would be "Ik eet gefruite uien uitsluitend in mijn geruite keuken", though.

It mostly gets confusing for me because of moving back and forth between English and Dutch grammar, but any bit of context would make it a lot less ambiguous :)