Fond is the concentrated, caramelized meat proteins and rendered fat left in a pan after cooking. It contains all the Maillard-created flavor compounds that make that steak or chicken taste exceptional. Most home cooks throw it away. Professional kitchens treat it like treasure. After you remove your protein and most of the fat, place the pan over medium heat and add liquid—wine, stock, or even water work. Use a wooden spoon to scrape and dissolve the fond, which takes maybe 30 seconds. The fond releases and emulsifies into the liquid, creating instant flavor. Add cold butter (1 tablespoon per ounce of liquid) off heat, whisking constantly, and you get a silky pan sauce that tastes like it took an hour. For gravies, let the fond develop uninterrupted over high heat for 2–3 minutes, then deglaze with stock or wine, scraping constantly. "Fond is where restaurant cooks hide their technique. It's the difference between a boiled sauce and an essential one." The emulsification is temporary—make your sauce right before serving, or it breaks. Add herbs or mustard after incorporating butter, never before. This technique works on any pan where protein has cooked, from a cast iron to a stainless steel skillet.