Place the dried beans in a deep bowl and cover with cool water by 2 inches. Cover the bowl with a light kitchen towel and all the Greek beans to soak overnight.
After soaking, drain and rinse the beans. Place in a stockpot with enough water to cover them by an inch and bring to a rolling boil. Cook for 5 minutes, then drain.
Transfer the beans into a large mixing bowl along with tomatoes, garlic, onions, celery, herbs, spices, olive oil and water. Stir to combine.
Pour into a 9x13" baking dish. Cover with foil and bake at 350°F for 90 minutes. Remove the foil and cook, uncovered, another 30 minutes.
Stir, then serve with crumbled feta cheese on top (or stirred in) and chopped parsley for garnish.
Notes
Gigante beans are giant butter beans (also known as giant lima beans). You can substitute with traditional sized dry lima or butter beans if you wish. If you use precooked, canned beans rather than dried, start with step 3 of the recipe instructions. Bake covered for 30 minutes, then uncovered for 15 minutes. For every pound of dried beans called for you'll need 58 ounces of canned beans (3 or 4 cans, depending on size).