Super Easy Gigantes Plaki (Greek Baked Beans)

Soak the gigantes beans overnight (or for up to 24 hours). When you're ready to use them, bring them to boil in a pot and let them simmer for 40-50 minutes until tender, but not completely done. Remove them from the pot and drain.
500 g gigantes beans
Heat the oven at 180C. Chop the onion and celery and add them to a tray with 2 tablespoon olive oil. Bake for 15-20 minute until soft.
1 large red or white onion
100 ml olive oil
Get the tray out of the oven and add all the other ingredients, including the drained beans. Add 100 ml hot water and mix everyhting well.
4-5 celery sticks
400 g canned tomatoes
1 tbsp tomato paste
2 tbsp oregano
1 tsp cinnamon
Salt and freshly ground pepper
Bake for another 60 minutes or until the beans are tender and the sauce is thick. The timing may vary according to oven, so keep an eye on it towards the end. The beans should not be mushy and you should be able to bite into them.
Serve hot or at room temperature with crusty bread and crumbled feta cheese (optional).