With the legumes that are so earthy it's good to have fresh elements in the salad like cucumber, peppers, cherry tomatoes and even red onion. I advice that you don't choose light green leaves because they tend to be very watery and their taste is lost with the strength of flavour from the legumes. Also if you're cooking the legumes yourself, cook them until they are al dente, not as much as you would if you were to purée them.