Mongolian sauce is a sweet and savory sauce that is often used in Chinese-American cuisine, particularly in dishes like Mongolian Beef or Mongolian Chicken. The sauce is made with a combination of soy sauce, hoisin sauce, brown sugar, and rice vinegar, along with other optional ingredients such as garlic, ginger, and red pepper flakes.

The sauce is known for its distinct sweet and savory flavor, which is achieved by the combination of the brown sugar and hoisin sauce. The sauce is typically used to marinate meat before cooking and is also used as a glaze or sauce after cooking.

Mongolian sauce can be used in a variety of dishes, including stir-fries, noodle dishes, and as a dipping sauce for appetizers.