Cut the tips of all the beans, and set the beans aside; you can discard the tips.
Heat in a large pot
Drop in the same pot and brown
Add
Wait until the cubes melt, stirring, and the mixture boils. Then, add the beans. If truly necessary, add water to (almost) cover the beans; but don't overdo it: the beans will soften while cooking and there should be just enough tomato sauce already to cover the softened beans.
Wait until the mixture boils again, stirring. Add
Let simmer, stirring regularly. The photo below shows what the pot looks like at this point: as the beans are still rigid, they stick out of the liquid.
In about 30 minutes or simmering and stirring, the beans will be soft, at which point they will be fully immersed inside the sauce. At that point, turn off the heat, and let the pot cool on the stove for at least one hour. Serve the beans warm (but not hot) with
Specifically, cut the feta into small cubes, serving one cube per person along with the beans. It's best to crumble the feta and mix with the beans before eating. You can also serve the beans over either