Pour great northern beans into a saucepan and cook over medium heat until very soft, about 30 minutes.
At the same time, place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until fork-tender but not mushy, about 12 minutes. Drain.
Transfer beans to a large bowl. Add avocado and mash. Add mustard, yeast, lemon juice, and salt; stir until mixture is smooth. Add potatoes, celery, and onion and mix well.
Chill for at least 30 minutes before serving.
If you use dried beans, soak them overnight and then pressure cook them for 30 minutes.
Source: Read Full Article