Heat the oil in a sauce pan over medium-high heat and cook the onions until soft and translucent, 5 minutes. Add the garlic and ginger and cook for another 2 minutes. Add the chicken and cook for 3-4 minutes. Add the sweet chili sauce, tomato sauce or ketchup, chili powder, peanut butter, and sugar and stir to combine. Add the coconut milk and salt and bring to a boil. Reduce the heat to medium-low, cover and simmer for 20 minutes, stirring occasionally. Add salt to taste.
Serve over steamed rice garnished with cilantro and chopped roasted peanuts.