Heat a large skillet (I prefer cast iron) over medium high heat. Add one tablespoon of butter. Thinly slice onions and bell peppers. Add onions first, sprinkle on a little salt and pepper, stir and cook five minutes. Now add the sliced peppers. Stir and cook five minutes more.
While the peppers and onions are cooking, lay out the meat on paper towels. If you were able to find thinly sliced steak*, it will be all stuck together in the package. You need to separate it so you can season it properly. Sprinkle meat with the Seasoned Salt. I really don't measure this, just sprinkle some on. You can taste it while cooking and add more if desired. *If you were not able to find pre-sliced beef, place your steaks in the freezer for about 10 minutes, which will make them easier to slice. And make sure you use a very sharp knife!
Remove onions and peppers to a serving dish and cover to keep warm.
Add remaining two tablespoons of butter to the same skillet, melt and then add the meat. Try to add it in one layer, but don't be too fussy about this. You just need some of it to sear, which adds flavor. Don't touch it for five minutes.
Now stir frequently until it's all cooked to your liking. There should be very little to no liquid left in your pan and meat should no longer be pink, with some of it showing those nice, browned parts.
Add in the worcestershire sauce, stir, give it a taste and adjust seasoning if needed. Turn off heat.
Build your sandwiches: I split my rolls, butter them lightly and toast in a dry skillet (you can do this while the meat is cooking), then lay on the sliced cheese (the heat of the roll will melt the cheese), then allow everyone to build their sandwich or bowl however they like!