Place the dried fava beans in a large mixing bowl and cover them with water. Allow the beans to soak overnight or for at least 8 hours.
Drain and rinse the soaked fava beans. Transfer them to a large pot and add 4 cups of fresh water.
Bring the water to a boil over medium-high heat. Reduce the heat to low, cover the pot, and simmer for about 1 hour or until the beans are tender.
Once the beans are cooked, remove the pot from heat and drain any excess liquid.
Using the back of a spoon or a potato masher, gently mash the cooked fava beans until they reach a desired consistency. Some beans should be mashed while leaving others whole.
Add the minced garlic, lemon juice, olive oil, ground cumin, and salt to the mashed beans. Stir well to combine.
Return the pot to low heat and cook the ful medamesi for an additional 5-10 minutes to allow the flavors to meld together.
Remove from heat and let it cool slightly.
Serve the ful medamesi warm in individual bowls, garnished with chopped parsley, tomatoes, cucumbers, and onions.
Drizzle extra virgin olive oil over the top and serve with lemon wedges and pita bread or crusty bread on the side.