Heat the olive oil in a large pot over medium heat. After 90 seconds when the oil is hot, add the onion, carrots, and celery. Sauté for 7-8 minutes until the vegetables soften.
Add the garlic, ginger, cumin, coriander, cardamom, cinnamon, black pepper and harissa paste. Continue to sauté for 2-3 minutes to bloom the spices.
Add the sweet potatoes, tomatoes, chickpeas, and vegetable stock. Bring to a boil, then reduce the heat and simmer for 20–25 minutes, until the sweet potatoes are tender.
Stir in the cilantro, parsley, kale, lemon juice, and salt to taste. Simmer for 4-5 more minutes, just until the kale is tender.
Meanwhile, toast the almonds in a dry skillet over medium heat for 2-4 minutes, stirring frequently, until lightly browned. Remove from the heat and set aside.
Ladle the soup into bowls. Garnish with toasted almonds, cilantro, parsley, plant-based yogurt, and additional harissa, swirled into the yogurt with the back of a spoon.