Whisk marinade ingredients to combine, then add to a bowl with chicken. Cover and refrigerate for an hour.
Using an immersion blender or stick blender, puree the mango and set aside.
Heat vegetable oil over high heat in large fry pan. Add marinated chicken and cook for 3-5 minutes, or until the chicken is white all over - it doesn't really brown due to the marinade.
Add mango puree and coconut milk or cream, stirring to combine. Turn heat to low and simmer for 15 minutes uncovered. Sauce will thicken.
Season with salt if needed. Remove from heat. Serve over steamed rice of choice. Garnish with cilantro leaves and chopped nuts if desired.
Video
Notes
Feel free to substitute 2 pounds chicken tenders or boneless, skinless thigh meat.
Use more or less garam masala seasoning depending on your taste for spicy heat. This is not a very hot dish, the spice blend is more flavorful than spicy. I think sometimes people confuse spices with heat, and there is a difference! 🙂
Use more or less cayenne, depending on the level of heat you like.