Which cooking technique involves immersing food in hot fat?

The technique that involves immersing food in hot fat is deep frying. This method typically requires the food to be fully submerged in oil, which allows it to cook evenly and quickly. The high temperature of the fat creates a crispy outer layer while sealing in moisture, resulting in a desirable texture and flavor.

In contrast, baking involves cooking food with dry heat in an oven, which does not involve any fat immersion. Sautéing uses a small amount of fat to cook food over relatively high heat, allowing for a different cooking environment where foods are often stirred or flipped. Boiling, on the other hand, involves cooking food in water or broth at high temperatures, where food is submerged, but it does not involve fat as the cooking medium. Thus, deep frying is unique in its reliance on hot fat for the cooking process.