Chicken Tikka with onion

For the chicken: 1 1/2 pounds boneless, skinless chicken breasts (3 to 4 breast halves total) 1/4 cup plain whole-milk Greek-style yogurt 2 tablespoons peanut[...]

6 garlic cloves , peeled 3 inches fresh ginger , peeled 2 -3 red chilies , deseeded olive oil 1 tablespoon mustard seeds 1 tablespoon paprika 2 teaspoons[...]

3 -4 boneless skinless chicken breasts (approx. 1.5 lbs) 2 tablespoons olive oil or 2 tablespoons vegetable oil 1 medium onion , finely chopped 1/2 teaspoon[...]