Thats a staple for me. No tomato sauce and I use a link not bulk sausage. Same onions, peppers and toss in a few chopped shishitos. I like that soft asiago airy bread cut short for a bun. Spread with light mayo and the lightest amount possible of stone ground mustard. Everything cooked in olive oil.
I got ravenously hungry just reading your version
of the sausage pepper sandwich.........scrumptious.