Heat the oil in a large stockpot or dutch oven. Add the onions and garlic and saute until just starting to soften, 3 - 5 minutes.
Add the cauliflower, sweet potato, and eggplant and saute for another few minutes. Add the spices, curry paste, salt, pepper and lentils and stir to combine. Cook for 1 - 2 minutes.
Add all of the liquid into the pot and stir to combine. Bring the soup to a boil, then cover and reduce to simmer. Cook for 30 - 40 minutes until the lentils have cooked and the sweet potato is fork tender. Add more water if needed.
Remove from the heat and stir in the greens. Continue stirring until the greens have wilted. Serve immediately with your choice of toppings!