In the paper we describe our work in using the Source engine from the game Half Life 2 to develop a serious game - Serious Gordon. Serious Gordon is used to teach principals of food safety and food hygiene in a restaurant kitchen environment. The target users of Serious Gordon are students of catering in the DIT Faculty of Tourism and Food. The paper describes the formation of the Serious Gordon team and the development of a story for the game. It continues with a description of the features from Half Life 2 that we retained and those that we removed for the game. We then describe the process we undertook to implement the game including a description of the tools we used. We conclude with a brief evaluation of the project and present future work.