Demi-glaze is a classic French sauce made from reduced meat stock and wine. It is a versatile sauce that adds richness and depth to many dishes. If you're looking for alternatives to demi-glaze, there are a few options to consider. One is a reduction of balsamic vinegar, which has a similar depth of flavor. Another option is a reduction of port wine, which has a sweet, fruity flavor. For a vegetarian option, you can use a caramelized onion and mushroom mixture as a base, adding vegetable broth and herbs to create a similar depth of flavor. Overall, there are several synonymous options for demi-glaze that can enhance the taste of any dish.