Fonds, or stocks, are the starting point for many sauces, it’s critical that stock quality be the absolute best possible (in flavor and color), especially when reduced.
Brown stock—made with browned beef or veal bones and classic vegetable aromatics (classically, onion, leek, carrots, and celery).
White veal stock—prepared with veal bones and classic vegetable aromatics, but the bones and vegetables are not browned.
Chicken stock—made with skin-on chicken meat, chicken bones, and classic vegetable aromatics.
Vegetable stock—typically made with classic vegetable aromatics and sometimes leftover bits of other mild vegetables, such as mushrooms.
Fumet—fish stock made with fish bones, heads, tails, and classic vegetable aromatics, except the carrots.
Court-bouillon—a quickly cooked broth prepared with classic vegetable aromatics that serves as a poaching liquid for meat or fish.
Demi-glace—any kind of stock—white or brown, typically using veal, chicken, pork, or beef—reduced down to a glaze (about 20 percent of its original volume) and later reconstituted in various sauces.
Glace de crustace—or crustacean stock, made with crustacean shells, such as shrimp, crab, lobster, or crayfish that is cooked with classic vegetable aromatics and cooked down to a glaze (about 20 percent of its original volume).