In a large sauce pan, sauté onion in olive oil over low heat until translucent. Mix dry spices in mortar or small bowl. Add crushed tomatoes, garlic, stock, spices, stir to mix and cook covered over low heat while cooking the chicken, stirring as needed to prevent sticking. Add oil to large non-stick skillet and preheat over medium heat. Cut chicken into pieces, trimming fat as required, coat with flour in plastic bag. Place chicken into skillet and turn up heat to medium-high. Cook chicken until almost done, flipping once and breaking up bunches to ensure even cooking. Add chicken to sauce and simmer covered for an hour or so, stirring as needed. Serve over penne pasta, couscous or rice, and garnish with cilantro.