Melt the butter in a saucepan over medium high heat.
Add the chicken, season with salt to taste, and saute until cooked through. Remove and set aside.
Reduce the heat to medium, and add the onion to the skillet. Saute until softened.
Mix in the garlic and saute for 30 seconds.
Add in the red curry paste, brown sugar, juice from one lime, ginger paste and fish sauce. Stir to combine.
Pour in the chicken broth and coconut milk.
Bring to a boil, and simmer covered for 20 minutes.
Stir the spinach into the pot and cook until wilted.
Return the chicken to the pot and simmer for another 5 minutes before serving.
Garnish with chopped peanuts, diced red bell pepper and chopped parsley before serving.