for the eggplant sauce:
Heat the oil in a large skillet and fry the eggplant on medium heat for about 15 minutes, or until nicely brown. Drain off as much oil as possible and discard it.
Add the tomato paste to the pan and stir with the eggplant. Cook for 2 minutes, then add the wine and cook for 1 minute.
Add the chopped tomatoes, water, salt, sugar, and oregano and cook for a further 5 minutes to get a deep flavored sauce. Set aside; warm it up as needed.
for the polenta:
Remove the husk and silk from each ear of corn, then chop off the pointed top and stalk.
Use a sharp knife to shave off the kernels - either stand each ear upright on its base and shave downward, or lay each ear on its side on a cutting board to slice off the kernels.
Place the kernels in a medium saucepan and cover them with the water. Cook for 12 minutes on a low simmer.
Use a slotted spoon to lift the kernels from the water and into a food processor; reserve the cooking liquid in a large pyrex measuring cup.
Process them for quite a few minutes, to break as much of the kernel case as possible.
Add some of the cooking liquid if the mixture becomes too dry to process.
Now return the corn paste to the pan and add back about half of the cooking liquid and cook, while stirring on low heat for 10-15 minutes, or until the mixture thicken to mashed potato consistency.
Add back more of the cooking liquid during this phase if you prefer a looser texture.
Fold the butter, the feta, salt and some pepper and cook for an additional 2 minutes.
Taste and adjust seasoning as needed.
Serve warm topped with a few spoonfuls of the eggplant sauce.