Drain the beans and place them in a large saucepan with the potato. Add just enough water to cover. Bring to a boil and cook over medium high heat, skimming the foam that rises to the top. When there is no more foam, stir in a generous pinch of salt. Continue cooking for an hour, stirring occasionally. Most of the water will have been absorbed into the beans. You may need to add a little more water. With an immersion blender or electric hand mixer, beat in olive oil. Adjust seasoning, adding more salt if necessary and pepper to taste.
While the beans are cooking, rinse the chicory. To a large sauté pan, add enough oil to cover the bottom. Add the garlic and pepper flakes. Heat until garlic starts to change color. Add the chicory and sauté until wilted and tender.
Fold the chicory into the purée. Place a generous portion of the bean purée into heated bowls.