In a large pot heat gently the olive oil over medium heat. Add the onion and cook for about 5 minutes, until the onion starts to soften.
Add cumin, turmeric, garlic, and stir for 1 minute until fragrant.
Then add lentils, carrots, potatoes, and give a good stir.
Add the broth, salt, and pepper and bring to the boil*.
Reduce the heat, cover with a lid, and simmer for about 20 minutes, stirring occasionally.
Remove the pot from the heat, check the seasoning and the consistency (you might like a thicker or a thinner soup, so you can add or reduce the amount of liquid - see notes)*.
Optional step: using an immersione blender you can puree the soup until it's smooth and creamy if you wish.
Serve with chopped parsley or coriander, a pinch of paprika if you like and freshly squeezed lemon juice to taste*.
