Pre heat the oven to 180 C. Linea large baking tray with parchment paper. Add the carrots, oil, salt and cinnamon to it.
Grab a piece of aluminium foil(15 by 15 centimetres is more than enough) and add a drizzle of olive oil over it. Place the garlic head, cut side down, over the foil and add a pinch or two of salt. Wrap the foil around the garlic head and put it in the oven, along with the carrots. Roast the vegetables for 45-60 minutes, or until the carrot sare tender and golden brown.
In a pot over medium-high heat, heat the stock and the water until boiling point. Once boiling, decrease the heat to low and let it simmer until needed.
Add the carrots to the bowl of a high speed blender. Squeeze the roasted garlic cloves out of their skins and add them to the bowl as well. Add the water and stock and process until smooth(you might have to do this in batches, as a regular blender doesn’t hold such amount of food and liquid all at once). Have a taste and adjust the seasoning if needed.
In the meantime, put a large skillet over medium heat and, once hot, add the hazelnuts and toast them for 2to 3 minutes or until golden brown. Place the hazelnuts into a clean kitchen towel and rub the towel to peel off their skins. Add the sesame, coriander and cumin seeds to the same skillet and toast until the spices smell fragrant and the sesame seeds have darkened just a bit.
Add the toasted nuts, seeds and salt to the bowl of a food processor and process until you have a sand-like mixture. Serve the dukkah over the soup along with a squeeze of lemon juice.The dukkah will keep, stored in a jar, for a couple of weeks.