Preheat oven to 200c or 400f
Add butternut squash to a oven proof dish, with 1 tablespoon of ghee, toss to coat and roast in the oven till softened and golden.
Add the other tablespoon of ghee to a large pot over a medium high heat and add the onion, garlic and ginger, cook until softened.
Add all the spices to a mortar and pestle, along with a little bit of water and mix together.
Add spices to onion, garlic and ginger mixture and stir to evenly coat.
Add lentils, stock and passata, bring to the boil and reduce heat, cover and simmer for approx 45 mins.
Add in the roasted butternut squash about 10 mins prior to serving time.
Serve with your choice of side