Charcutière sauce (often referred to in a 500g context as a standard jarred quantity or a batch recipe amount) is a classic French, tangy, savory compound sauce specifically designed to accompany pork dishes, such as chops, sausages, or roast pork. 
Definition & Flavor: The name literally translates to “sauce of the pork butcher”. It is a variation of sauce Robert (a brown mustard sauce), characterized by a base of sauce Espagnole (brown sauce) that is elevated with white wine, onion, and sharp, chopped cornichons (gherkins).
Key Ingredients: The sauce generally consists of white wine, onions or shallots, mustard (usually Dijon), and finely diced pickles.
Best Pairings: It is ideal for grilled, pan-seared, or sautéed pork, as the acidic, tangy flavor cuts through the rich, fatty meat.
Serving: It is often made by deglazing the pan used to cook the pork, resulting in a rich, velvety sauce that is served warm. 
While sometimes available in pre-prepared jars, it is commonly made from scratch in roughly 30 minutes, with 500g-type recipes often yielding enough sauce for a large family meal or a restaurant-level service for 4-6 people.