1. Preheat oven to 375°. Place onion and garlic in a food processor; process until a smooth paste forms. Spoon half of paste into a small bowl; cover and chill. Add 1 teaspoon cumin, 1 teaspoon red pepper, and ginger to remaining paste in food processor; process until smooth. Stir in yogurt and lemon juice.
2. Combine chicken and yogurt mixture in a large zip-top plastic bag; seal and marinate in refrigerator 2 hours.
3. Remove chicken from bag; discard marinade. Sprinkle 1/2 teaspoon salt evenly over both sides of chicken. Place chicken on a rack coated with cooking spray; place rack in a foil-lined pan. Bake at 375° for 16 minutes or until done, turning after 8 minutes. Let stand 10 minutes; cut chicken into bite-sized pieces.
4. Heat a large nonstick skillet over medium-low heat. Add oil to pan; swirl to coat. Add cinnamon stick; cook 1 minute or until fragrant, stirring frequently. Stir in 1 teaspoon cumin, 1/2 teaspoon red pepper, 1/4 teaspoon salt, coriander, and turmeric; cook 1 minute, stirring constantly. Reduce heat to low; stir in reserved onion-garlic paste. Cook 12 minutes or until lightly browned, stirring occasionally. Stir in tomatoes; bring to a simmer over medium heat, and cook 8 minutes, stirring occasionally. Stir in half-and-half and milk; bring to a simmer. Stir in chicken; simmer 2 minutes or until heated. Sprinkle with cilantro.