Pick/separate the dirt from the beans and rinse.
I used a pressure cooker to boil the beans and this makes it faster. If you don't have one feel free to use a pot.
Add beans to the pot and pour water enough to cover it, and boil it for about five minutes (this reduces indigestion or bloating and also get rid of the preservative on the beans if there's any) and drain the water. This step is optional, you can just boil until tender.
Add another water to the beans, onion, cover, and boil until very tender. Add salt to taste.
When the beans are all soft, use a ladle, potato masher a hand mixer to mash the beans.
When the mashed beans get cold it tends to get drier so you might want to adjust the water to your preference also it gets thicker so adjust the consistency to your preference. Ewa Agonyin is ready.
Serve Ewa Agonyin with stew (I'll add the link of the stew recipe) and enjoy it.
Make the recipe yours, if you want it thick and all mashed or partially mashed, it won't alter its taste. Just make it the way you would enjoy.