I need to attach my grill to my deck to deter it from being stolen. What do you recommend?

Aircraft cable is a good choice. You can swage both ends and use it with a padlock. It's more attractive than a heavy chain, and it can be used on many things - such as outdoor furniture.

Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the North American Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.