In a large skillet, heat 2 tablespoons olive oil over medium heat and sear chicken, seasoned with salt and pepper, 3 to 5 minutes per side until golden.
In a large food processor or blender, add bell pepper, onions, garlic, paprika, coriander, cayenne, 1 teaspoon cumin, ginger, turmeric and juice of 1 lime, 1/2 cup yogurt. Blend 1 to 2 minutes until smooth.
In a large slow cooker, add chicken, tomatoes, ingredients from blender, chicken broth, cover and cook on LOW for 8 hours until chicken is cooked through.
In a small bowl, add remaining yogurt, cumin and lime juice. Stir to combine and serve with the chicken mixture.