So whole wheat then?

Yesterday I set out to make black bean soup but it just kept getting better and better and wound up as chili instead. Also it was chilly, yesterday, so that worked out fine. Today there's just a little bit left over and I don't want to go to the trouble of heating it up for lunch so I'm thinking just squish it between a couple of breads and make a chili sandwich. What could possibly go wrong with that?