1) Heat the oil and butter over medium heat in a large soup pot. Add the almonds and stir until toasted, about three minutes. Transfer nuts with a slotted spoon to a small plate and reserve.
2) Add the carrots, onion, salt, cumin, coriander, ginger, and pepper to the pot and cook, stirring occasionally until tender, about ten minutes. Increase the heat to high and cook until the vegetables brown, about 4 minutes more.
3) Add the water and chickpeas to the pot. Bring the soup to a simmer and cook until the beans are very tender, about 10 minutes.
4) Meanwhile, stir together the yogurt, coriander, and lemon zest in a small bowl.
5) Roughly chop the reserved almonds. Transfer half of the almonds and half of the soup to a blender. Pulse at first, and then puree, to make a smooth soup base. Return the pureed soup to the pot and heat. Stir in the yogurt mixture, divide among warmed bowls, and serve with the remaining chopped almonds sprinkled on top.