Cook bacon in skillet until crisp. Remove and drain. Discard all but 1 T bacon grease.
Add onions to skillet and cook over medium until softened and starting to caramelize. Remove onions to paper towels and drain.
Add ham to skillet and saute for 2-3 minutes to brown.
Combine cheese, sour cream, mayo, & Worchestershire.
Spread top and bottoms of rolls with spread.
Top bottom of rolls with 2 Tb onions and then 1 bacon slice broken in half.
Place1 ham slices on top of everything and then add roll top, spread side down. Place sliders in a dish that will keep them tightly together.
Combine butter, mustard, Worchestershire, and garlic salt. Brush tops with mustard mixture.
Cover dish . Bake at 350 for 15 minutes, uncover and bake for 10 more minutes.