In a large saucepan, cover the beans with 2 inches of water and bring to a boil.
Reduce the heat to low and simmer, stirring occasionally, until the beans are just tender but still al dente (~ 2 ½ - 3 hours). Add water as needed to keep the beans covered by roughly the same amount
Season with a strong pinch of salt and let stand at room temperature for 5-10 minutes. Reserve 1 ½ cups of their cooking liquid before draining the rest
In your food processor or blender, add the olive oil with the oregano, parsley, garlic and a pinch of salt; pulse to a coarse puree.
In a large saucepan, over medium-high, warm 3 Tbsp of the olive oil.
Add the onion and garlic; cook until softened (~ 8-10 minutes)
Add the tomatoes, oregano and the reserved cooking liquid from the beans. Reduce the heat to low and simmer, stirring occasionally, until the sauce has reduced to 1 ½ cups (~ 1 hour)
Season the tomato sauce with salt, to taste.
Preheat the oven to 425°.
In a 9-by-13-inch baking dish, mix the beans with the tomato sauce and sprinkle with feta.
Bake in the upper third of the oven for about 40 minutes, until the beans are bubbling and the cheese has browned. Remove the from the oven and let stand for 10-15 minutes.
Meanwhile, in a skillet, heat the remaining 2 Tbsp of olive oil.
Add the bread crumbs and cook, stirring occasionally, until toasted, (~ 3 minutes)
Top the beans with toasted bread crumbs, a spoonful of oregano pesto, and serve.