Step by Step Photos. Return the chicken and any accumulated juices to the pan and simmer until the sauce is thickened and the chicken is cooked through, 2 to 3 minutes. Prepare the marinade first, by stirring together 2 Tbsp olive oil, 2 Tbsp brown sugar, 1/4 cup balsamic vinegar, 1 Tbsp soy sauce, 2 cloves of minced garlic, and some freshly cracked pepper. Scroll down for the step by step photos! Stir in 1 cup half-and-half or whole milk, 1/2 cup chicken broth, and 2 tablespoons balsamic vinegar until no lumps from the flour remain. Reduce the heat to a simmer. Bring to a boil.