In a large bowl, combine yogurt, lemon juice, 2 teaspoons cumin, cinnamon, cayenne, black pepper, ginger, and 4 teaspoons salt. Stir in chicken, cover, and refrigerate for 1 hour.
Preheat a grill for high heat.
Lightly oil the grill grate. Thread chicken onto skewers, and discard marinade. Grill until juices run clear, about 5 minutes on each side.
Melt butter in a large heavy skillet over medium heat. Sauté garlic and jalapeno for 1 minute. Season with 2 teaspoons cumin, paprika, and 3 teaspoons salt. Stir in tomato sauce and cream. Simmer on low heat until sauce thickens, about 20 minutes. Add grilled chicken, and simmer for 10 minutes.