cook up

To prepare (food or chemical substances) by cooking or heating.

To manufacture; to invent (something, often a deceit or falsehood); to counterfeit (something).

To prepare (heroin, opium, crack, or meth) by heating or otherwise manufacturing.

To manufacture a significant amount of illegal drugs (LSD, methamphetamine, etc.).

Used other than figuratively or idiomatically: see cook, up.