Add vegan butter to a medium saucepan over medium heat. When it's hot, add cumin seeds and stir for 1 minute.
Add onion to the butter and cook for 5 minutes, until translucent. Add the ginger, garlic, and serrano pepper. Cook for about 2 minutes.
Add ground spices, making sure that they don't stick to the pan. Add a splash of water if they start to stick to the pan.
Add tomatoes and cook for 7-8 minutes, or until the tomatoes' juices have evaporated and it all starts to stay together.
Coat the butternut squash and red lentils in the tomato mixture for a couple of minutes. Add 3 cups water and 1 tsp salt. Bring heat to high and reduce to medium or medium-low heat. Cover and maintain a steady simmer for 20 minutes, or until the butternut squash is soft. Uncover and stir occasionally during this time, just to make sure nothing is sticking to the bottom of the pan.
When the butternut squash and lentils are soft, pour in coconut milk and add kale. Cook uncovered for 3-4 minutes.
Add pepper. Taste and decide if it needs more salt and/or chili powder. Finish with 1-2 tbsp lemon juice and cilantro.
Serve with rice, roti, or naan!