In a large cast-iron skillet set over medium-high heat, add 2 tablespoons oil. Sear the chicken on both sides, about 2 to 3 minutes each side. Remove and set aside.
Reduce heat to medium. Add cumin, cinnamon, chili powder and garlic powder. Stir until fragrant, about 15 seconds. Add onions and tomato paste and continue to saute for about 4 minutes.
Add almond butter, stirring to incorporate everything. Add stock and chocolate, stirring until chocolate has melted. Bring to a simmer. If sauce is too thick, add 1/4 cup water.
Return the chicken to the skillet and nestle into the sauce. Cover, simmer until the chicken is cooked, about 15 to 20 minutes. Serve on top of rice, sprinkled with cilantro and sesame seeds.