Start your answer by defining Chef. It is an automation platform that is particularly used for transforming infrastructure into code. It uses pure-Ruby domain-specific language to write system configurations.
Now you can explain the architecture of Chef and how it works.
Chef architecture consists of three core components:
Chef Workstation, Chef Node, and Chef Servers.
Chef Server: The chef Server is the core point for infrastructure configuration data. It stores, configures, manages, and presents the configuration data to all components.
Chef Workstation: Workstations are the hosts where you can create, test, and modify your cookbooks and configuration data.
Chef Node: These are the servers managed by the Chef. Chef client is installed on each node which is under management by Chef. Chef clients run on the nodes to contact the chef server for the information required to configure the node.