Preheat oven to 350 degrees.

In a saute pan (or oven proof casserole dish such as Le Creuset) saute the leeks over low to medium heat until soft, about 5 minutes. Add the salt, garlic, and oregano and remove to a separate plate or bowl.

Combine the leeks with the greens.

Place half of the greens/leek mixture in the bottom of the casserole dish.

Cover with beans and then with the remaining greens.

Pour the can of tomatoes over the bean/greens mixture.

Cover and bake for 30 minutes (can also be cooked on low heat on top of the oven for 25-30 minutes).

Serve.

*Allow to cool, place in appropriate container or ziploc bag, label and freeze up to 4 months. When ready, just heat in a pot over low-medium heat or defrost in fridge for 24 hours.