Easy Chicken with mustard

4 (6 ounce) boneless skinless chicken breast halves 1/4 teaspoon salt 1/4 teaspoon fresh ground black pepper 2 tablespoons all-purpose flour 2 tablespoons[...]

4 large skinless chicken breasts , cut into chunks 3 tablespoons vegetable oil 1 teaspoon mustard seeds , brown 1 large onion , sliced 3 garlic cloves ,[...]