Step 1

Put the walnuts and garlic in a food processor and process until finely chopped, stopping machine and scraping down sides as necessary. Add the vinegar, 2 tablespoons broth, salt, cayenne and black pepper and process until it forms a chunky paste. Add additional broth if necessary.

Step 2

Add the well-drained beans to the processor and pulse about 6 to 8 times, enough to crush most of the beans but not puree them.

Step 3

Scrape the mixture into a large container and stir in half of the parsley and green onions. Sprinkle the rest on top. Cover and refrigerate for at least an hour to allow flavors to blend. (The flavor improves with age, so if you have time, let it chill for several hours or overnight.) Check seasonings and add more vinegar, pepper, or salt to taste.