In a large pot over medium-high heat, warm the oil. Add onion and pinch of salt. Saute for 5 minutes, stirring occasionally, until soft and translucent. Stir in the garlic and cook for an additional 1 to 2 minutes, stirring occasionally, until fragrant. Add the curry powder and stir.
Add in the vegetable stock, wild rice and sweet potato. Stir to combine. Continue cooking until the soup reaches a simmer. Then reduce heat to medium-low, cover and simmer for 30 to 40 minutes until the rice is tender, stirring occasionally.
Add the coconut milk and spinach to the soup, and stir gently until combined. Taste and season with salt and pepper, if needed.