Start by dry roasting the nuts and flax seeds in a frying pan over medium heat. Then add the sugar and lemon juice and continue to cook until the sugar has dissolved and coated the nuts. Promptly transfer the nuts to a sheet of baking paper, spread them out and leave them to cool. Once chilled, roughly chop the candied nuts.
Heat the oil in a pan and then add the onion, garlic, and ginger. Sauté the mixture until the onions are translucent, then add the beetroot, and sauté for a couple of minutes. Add the water and bring everything to a boil. Season with the dukkah and salt, and simmer over low heat for about 20 minutes. Just before it’s done, add the lemon juice and simmer for a few more minutes. Puree the soup before serving in bowls. Garnish with some crème fraîche (or cream) and the candied nuts.