Heat oil in a large saucepan and over a medium heat and cook onion and carrot.
Cook for 3-4 minutes until the onion becomes clear. At this stage add the garlic, cumin powder, coriander powder, turmeric powder, and dried chilli. Cook for a further 2-3 minutes to release the aromatics.
Add the lentils and the stock and bring to the boil. Reduce the heat, place the lid and simmer for 20 minutes until the carrots and lentils become soft.
Meanwhile make the coriander pesto:
Blend or process the coriander, garlic, and pistachios until finely chopped. Slowly add the oil and lemon juice as a slow and steady stream whilst mixing, blending until even. Season to taste.
Check the soup and remove from the cooktop and place in a blender. Secure the lid and blend until smooth.
Return the soup to the saucepan and season with salt and pepper. The lentils will help to thicken the soup, so add a little water if necessary.
Carefully pour the soup into a bowl, and dress with some of the coriander pesto. Garnish with fresh coriander leaves and cracked pepper.
Serve with your favourite crusty bread, like Sourdough or Ciabatta.