What term describes an item or substance used as a decoration or embellishment accompanying prepared food?

The term that accurately describes an item or substance used specifically as a decoration or embellishment accompanying prepared food is "garnish." Garnishes are typically edible items that enhance the visual appeal of a dish, adding color, texture, and aesthetic value without necessarily altering the main flavor profile of the dish. Examples of garnishes include herbs, edible flowers, and decorative cuts of fruits or vegetables.

In contrast, presentation refers to the overall arrangement and visual display of the dish but does not specifically identify the decorative items used. Condiments are usually sauces or seasonings added to enhance or alter the flavor of a dish, such as ketchup or mustard, rather than serving a decorative purpose. Accompaniments typically refer to additional food items served alongside the main course that complement it, rather than being purely decorative. Thus, "garnish" is the most precise term for embellishments used specifically for decoration.