Classic sandwich inclusions?

I love a sandwich with pickle and mustard. Before i went veg theyd probably go on rye with pastrami. I feel like i havent quite nailed a veg version of a classic deli sandwich. My best shot involves big slices of a decent quality tomato with salt sprinkled right on. I also think a good cheddar helps with the salt level. Any surprising ingredients help bring the salty/savory youd get from meat, or that you just like in general? Recommendations on greens? Whats your go-to sando?