Slice beets off of stems, leaving about 1/2 inch of the stem intact. Wash beets thoroughly, but do not peel. Line a sheet pan with foil and place beets on pan. Sprinkle with a 2 tablespoons of the olive oil, a little salt and pepper and add about 1/4 cup of water to pan. Cover with foil. Roast for about 30-40 minutes, depending on size of beets, until they can be easily pierced with a knife. Keep warm.
Place pine nuts in small fry pan and, stirring over medium heat, toast until lightly golden. Set aside.
Bring a pot of well salted water to a boil. Slice beet green stems into 1 inch pieces. Slice greens into large slices.
n a large saute pan, fry the pancetta until just crispy. Remove with a slotted spoon and set aside. If there is a lot of fat, drain fat but do not wipe pan clean. Add about 2 tablespoon of olive oil to pan and place onions in pan. Saute over medium heat for several minutes, stirring once in a while. Add garlic and cook for 2 more minutes. Add red wine vinegar and cook for 2 more minutes.
Add beet stems and 1/4 cup water, cover and cook for about 10 minutes. Add beet greens and return pancetta to pan. Cook, covered for about 10 more minutes. Meanwhile, add the pasta to the boiling water and continue on with the sauce.
Add half of the pine nuts to the sauce and stir. Season with salt and pepper, keeping in mind that the pancetta is salty. Turn off heat.
Remove skins from beets by either peeling them off or taking a small sharp knife and removing them. Slice into quarters.
Remove pasta from pot with a strainer and add to the saute pan with the sauce. Also add about 1/4 cup of the pasta water. Thoroughly mix the greens and pasta together until pasta is nicely covered with the sauce.
Transfer the pasta and sauce to a serving bowl or platter. Arrange beet quarters around dish and sprinkle them with sea salt. Top pasta with remaining pine nuts.