4. Step
Whisk cream, vinegar, mayonnaise, cornstarch, onion powder, garlic powder and the remaining 1/4 teaspoon each salt and pepper in a measuring cup. Increase heat to medium-high and pour the cream mixture into the pan. Bring to a simmer and cook, stirring, until thickened, about 2 minutes. Return the chicken and broccoli to the pan and sprinkle with herbs; cook, stirring, until heated through, 1 to 2 minutes more. Garnish with pepper, if desired.