Place the cauliflower and sweet potatoes in a baking dish, drizzle with olive oil and bake for 30 minutes until soft. You can also soften them in the microwave. Cool and mash with a fork.
Chop the onion and vegetables in a food processor, transfer to a bowl along with the potatoes, cauliflower, and other meatball ingredients. Chill for two hours in the refrigerator.
Form balls and fry on both sides until golden brown. Remove to a strainer/paper towel.
Stew:
Saute the onions in a pan with olive oil until golden brown.
Add the garlic cloves and spices and fry for a minute. Add the sweet potatoes, chestnuts, and chicken meatballs. Fill with water until almost covered, cover and cook for 30 minutes.
Remove the lid and transfer to a preheated oven at 355F (180C) for another 30 minutes.
Remove from the oven, sprinkle with parsley, and serve.