Drain and rinse chickpeas. Place in a bowl and mash with a fork.
To peel the chestnuts, you must boil them first: Place chestnuts in a saucepan and fill with excess cold water. Bring to a boil on medium-high heat. Cover with a lid and reduce heat to low. Let it simmer for about 5 minutes. Keep them in warm water until you are ready to peel them.
Peal potatoes and sweet potatoes. Cut in chunks.
Chop celery, onions, carrots and tomatoes. Blend them together in a food processor with leaves from 1 rosemary branch and 4 leaves of sage.
Add raw potatoes, sweet potatoes, chopped dandelion, extra virgin olive oil, salt and mashed chickpeas into a large saucepan. Cover with excess water and close lid. Let it cook on medium-low heat for a half hour until potatoes and yams are tender and easily pierced with a fork.
Spoon out the tender potatoes and sweet potatoes and place them in a bowl. Mash the potatoes together and place them back into the saucepan.
Cook for another 5 minutes on medium-low heat. Serve hot.