Hi Amy - honestly it is your choice. If you cut them then no slits are needed - they are just to allow the brine to get inside more easily. Personally I'd suggest you make the rings good size if you go that route as they tend to shrivel a bit.

You do have to remove the stems and nipping off the blossom end is also suggested so given that removing the core and seeds is easy and that is what we do with ours. But it isn't required and some prefer to leave the seeds in.

Link below is to an NCHFP recipe specifically for Banana Peppers if interested. You'll find several other recipes for peppers there too. There are also several other discussions here with different recipes in them but the search is down right now so I can't pull them up for you. But check them out when the search comes back online.

Dave

Here is a link that might be useful: Pickling Banana Peppers

i believe the yellow peppers at Subway are hot banana peppers.

WM