Slice onion into thing rings
Butter the buns
Halve the wieners, but not cutting through
Melt butter on pan, caramelize the onion slices
On other pan, melt butter and brown the hotdogs and the buns
Lay cheddar cheese slices on the browned buns
Lay a hotdog, top it with caramelized onions, and add relish, mustard, ketchup