Painted Pony beans pate
Well basil and garlic could fit well with the walnuts (think about pesto, basil, garlic, cheese and nuts).

With the bean paste... I don't know, I guess it depends what kind of tone you would like to give to the dish.
Stated that the only way to know is to try, I would also try with nutmeg and, if you're brave, maybe even a pinch of cinnamon!