Start by washing your red lentils thoroughly and leave them to soak for about 15 minutes.
While the lentils are soaking, peel and chop your pumpkin, onion, carrot, and celery.
In a large pot, heat the olive oil over medium flame.
Add the minced garlic and chopped onion to the pot. Sauté them until the onion turns translucent.
Add the chopped pumpkin, carrot, and celery to the pot.
Now, drain the soaked red lentils and add them to the mix.
Stir in the ground turmeric and ground cumin. Season with salt and black pepper.
Pour in the vegetable broth and bring the soup to a boil.
Reduce the heat and let the soup simmer for about 25-30 minutes, or until the pumpkin and lentils are tender.
Using a hand blender, blend the soup till it reaches a smooth consistency. If you like your soup chunky, you can skip this step or blend partially.
Finish off with a splash of lemon juice and stir well.