When the beans are done or nearly done, add the olive oil to a very large all-in-one pan or Dutch oven. Add the onion and cook until soft and browning; the trick is to let the onion sit for a bit once heated, so it develops some brown spots.
3 tbsp olive oil, 1 medium yellow onion
Add the garlic, tomato paste and oregano. Mix well until aromatic.
2 tbsp tomato paste, 2 tsp oregano, 4 cloves garlic
Add the tomatoes, sugar and salt and stir well. Let it simmer down some, but it should remain quite saucy. Taste for flavors here and add anything additional, like salt, pepper, more oregano, etc.
28 oz crushed tomatoes, 2 tsp salt, ½ tbsp honey
Preheat the oven to 350ºF.
Drain the beans but reserve the liquid and discard the onion halves and other spices. Gently mix in the beans. If the mix is looking a little dry, add some of the bean water. You want the beans to be fully submerged and the sauce to be fairly liquid, as it will cook down in the oven further.
Bake for 30 minutes. Serve hot, at room temperature or cold.