Soak beans: Place the washed beans into a large bowl. Cover them with plenty of water; they will swell a lot. Add the baking powder, stir, and soak overnight.7 oz dried fava beans + 1 tablespoon baking soda
Peel fava beans: Drain and peel the beans, discard the peel and any beans that have wormholes in them.
Cook beans: Place the peeled beans into a large pot and cover them with plenty of water. Bring to a boil, turn the heat down, and simmer for 30 to 45 minutes. Start checking after 30 minutes already; the fava beans should be tender but not mushy. If they are not done yet, keep checking every 5 minutes.
Reserve some cooking water: Drain the beans and reserve some cooking water. If you use already cooked beans, you can use plain water for the dip.
Saute: Chop the onion very finely. Heat 1 tablespoon olive oil and cook the onion for about 3-5 minutes until soft. Stir often. Add the grated garlic cloves and the cumin seeds and cook, stirring constantly, for another minute.1 medium onion + 1 tablespoon olive oil + 4 garlic cloves + ½ teaspoon whole cumin seeds
Combine: Place the cooked fava beans into a food processor. Add the onion mixture, about ¾ of the reserved cooking water, lemon juice, olive oil, and some salt and pepper.¾ from ½ cup water or cooking water from the beans5 tablespoons freshly squeezed lemon juice + 4 tablespoon olive oil + fine sea salt and pepper
Process until very smooth, stopping the food processor a few times in between and scraping its walls properly. Adjust the consistency with some of the remaining water, if necessary. Add more salt, pepper, and lemon juice to taste.
Notes
Beans: You will have about 2 ½ cups/ 450 g/ 1 lb cooked fava beans