Chicken Stroganoff

Name: Chicken Stroganoff
Ingredients: 2.2 pounds (1 kg) boneless, skinless chicken breast; Salt and freshly ground black pepper to taste; 6 tablespoons olive oil, divided; 1 medium yellow onion, chopped; 3 garlic cloves, minced; ½ cup dry white wine; ½ cup tomato sauce; 2-1/2 cups chicken broth or stock; 2 tablespoons unsalted butter; 1 pound (about 450 g) fresh common white button mushrooms, cleaned and sliced; ¾ cup heavy cream (sour cream, plain or greek yogurt, or coconut milk can be substituted for the heavy cream); 1 tablespoon dijon mustard; ¼ cup fresh parsley or cilantro, chopped