Heat the oil in a large saucepan over medium heat. Add the onion, celery and carrot and stir for 6-7 minutes or until soft. Add the garlic and curry powder and stir for 1-2 minutes or until aromatic. Add the sweet potato. Stir until combined.
Stir in tomato, water and coconut milk. Bring to the boil. Reduce heat to low. Simmer, partially covered, for 20 minutes or until sweet potato is just tender. Stir in sugar and half the peanuts. Cook, stirring occasionally, for 3-4 minutes to develop the flavours.
Stir in the spinach. Cook for 1-2 minutes or until the spinach just wilts. Divide the stew and rice among bowls. Top with remaining peanuts.