In large, heavy saucepot over medium-high heat, heat oil. Add onions and chorizo; cook until onions soften and chorizo starts to brown, about 10 minutes.
Add ham-flavored concentrated mixture and ham hock; bring to boil. Add potatoes and turnip. Reduce heat to medium low. Simmer, stirring occasionally, skimming off and discarding any foam that rises to the surface, until ham, potatoes and turnips soften, about 25 minutes.
Add cannellini (with their liquid) and greens; cook until greens are tender, about 20 minutes more.
Remove ham hock; cut ham off bone. Discard bone. Stir ham into pot. To serve, divide soup among serving bowls.