I just made this for a quick lunch, and it turned out fine, but warning: don't add the salt unless you are using low-sodium black beans. I didn't add any salt and the taste was quite salty. Test first, before you season!
The recipe calls for 1 tsp. of salt. I am not sure how that got there! Perhaps something was lost in translation, but the recipe is supposed to call for a dash of salt (and even that is optional). It might taste OK with a whole teaspoon, but I wouldn't know because I rarely use any salt.