I am unfamiliar with navy beans (I know what they are; they're just not popular in CA). So, I subbed cannelini. So glad I did; the cannelini's smooth flavor contrast with the black bean's earthyness was fabulous. Of course, mango was a sweet & lucious counterpoint. By the way, I used dried beans in my slow cooker, not canned. So much more creamy and flavorful than canned, which is always a little "off", or salty. I usually have black beans around to sneak in a little protein/fiber here & there. I had bought the cannelini to mix things up, but hadn't been inspired to cook/use them. Great fortune to come across this recipe. Thanks allrecipes newsletter!