InstaMash

 is a food item found in Fallout 3. It can restore some of your Hit Points, but also gives you a small amount of radiation.

Insta-Mash is packaged in a white box with blue highlights. A tag-line toward the bottom of the box states that Insta-Mash comes with "With Real Dig-In Flavor!"

The "insta" part of the name most likely indicates that the contents is powdered and requires added water to swell, similar to instant mashed potatoes, though the bottom tag could indicate that the powder is somewhat synthetic to which one could see as a spoof of modern cookery and cheaper production. You get some InstaMash with the Megaton house and the Tenpenny Tower suite after purchasing the Pre-War theme.