Add the butter beans to a large cooking pot or stockpot. Pour enough room-temperature water to cover the beans by 4 cm, then soak them overnight.

Bring the pot to a boil.

Skim the froth from the beans and cook for a minute.

Drain the butter beans in a strainer. (throwing away the water removes pesticides from their skins and makes the beans more digestible).

Transfer the beans back to the cooking pot along with 2 liters (8 cups) of hot water or stock.

Season with coarse sea salt.

Simmer the beans covered at low heat for 40 minutes to 1 hour (or until the beans are tender).

Preheat oven to 400°F / 200°C.

In a saute pan, heat a good splash of olive oil.

Saute the onion and garlic until soft and translucent.

Add the fresh chopped tomatoes (if using canned, add them together with the passata) and tomato paste. Season with coarse sea salt. Cook for a minute or two until it looks mushy and drained.

Add the carrots and celery, then give it a few stirs.

Pour in the tomato passata, remaining seasonings (bay leaf, paprika, oregano, parsley, dill, pepper), and the extra virgin olive oil.

Pour 2 cups (500 ml) of hot water and cook the sauce over low heat, uncovered, until it thickens.

Transfer the cooked beans to a large baking dish or baking pan along with their cooking water.

Add the sauce and shake the pan to combine.

Bake for about 40-45 minutes, or until the sauce thickens (keep in mind that the beans will absorb more of the sauce as they cool, so don't let it get too thick). Stir once or twice while the beans bake.

Let the beans sit for 15-20 minutes before serving to absorb the sauce even further.

Serve with freshly ground pepper, a piece of feta cheese, and Kalamata olives on the side for a true Greek meal!