Optional Step: Smoke your chicken pieces for a few minutes to add some smokey flavor.
Slice open the chilies and remove the ribs and seeds.
Heat a large skillet over high heat. Add the chilies and tomatoes and cook until nicely charred all over, not burnt. Remove from the pan and place in a bowl.
Peel the garlic and ginger and finely grate into a small bowl. Add most of the garam masala, a pinch of sea salt and black pepper, and 1 tbsp of the Greek yogurt. Coat the chicken pieces with the mixture.
Return the pan to medium heat and add 1/2 tablespoon olive oil. Cook the chicken pieces until they reach an internal temperature of 165°F. (About 5-10 mins for pre-smoked chicken or 10-15 mins for raw.) Remove from heat.
Remove the skins from the tomatoes and roughly chop the chilies. Add to the chicken and mix well.
Stir in the cashew butter and 3/4 cup boiling water. Stir well.
Return the chicken to the stove over medium heat for a few minutes until heated through and thickened a bit.
