In a medium sized bowl, whisk together the coconut milk and curry paste. Set aside.In a large dutch oven or pot, heat the oil on medium high until shimmering and then brown the chicken for several minutes.Stir in the onion, bell peppers, potatoes and tomatoes. Add the coconut milk mixture and stir. Bring to a boil, cover, and turn the heat down to low. Simmer for 20-30 minutes or until the potatoes are soft and chicken is cooked through. Remove from the heat and stir in the cilantro.Serve over rice if using and garnish with peanuts.