The Food Network app is supported on Apple TV (beginning with the 4th generation), and the app is available to install from the Apple TV app store. After installing, activate the app by visiting www.foodnetwork.com/appletv.
You will need to sign in with your service provider credentials to watch the newest TV episodes on Watch Food Network. There are, however, a variety of clips, episodes and original content at FoodNetwork that are accessible without signing in.
Food Network Store is working diligently to complete agreements with all Food Network Store's partners. For now, you can enjoy some videos on Apple TV without logging in by looking for videos without a key icon.