Preparation:
Heat the olive oil on medium to high heat, in large heavy non stick pan, and add the onion. Turn down the heat to medium – low and cook, stirring constantly until the onions are soft and golden brown, around 20-30 minutes. Take out of pan and set aside. Place the black beans in a large pot with water enough to cover 8 cm. Bring to a boil. Drain them and put them back in a pot with fresh water to cover them. Bring to a boil and turn down the heat to medium low and simmer until soft but not mushy, for 45 minutes. Five minutes before removing the pot from the heat season with salt. Remove and drain. Put them in a bowl and mix with the olive oil, vinegar, parsley and chopped onions. Spread the caramelized onions on top.