“Premium Bordelaise Wine Sauce 300g” generally refers to a high-quality, pre-prepared version of the classic French Bordelaise sauce, packaged in a 300g container (typically a glass jar or pouch). 
This sauce is designed to bring a restaurant-quality, rich finishing sauce to home-cooked meals without the time-consuming effort of making a demi-glace from scratch. 

Characteristics and Composition
Flavor Profile: A rich, savory, and deep red wine reduction that is velvety in texture.
Key Ingredients: Typically made from a base of dry red wine (often Bordeaux), demi-glace (intense beef stock), shallots, and butter.
“Premium” Definition: In a retail context, “premium” indicates it likely uses higher-quality stock, authentic wine, and potentially includes traditional bone marrow or veal jus for a thicker, more luxurious texture.
Usage: A “300g” size is typically designed for multiple servings, perfect for pairing with steak, prime rib, or roasts.