If you only want one year of premium (or one month) without having the subscription renew automatically, you can simply sign up for premium and then unsubscribe once you've been charged for the subscription. This will set your account to cancel at the end of the billing cycle you've paid for instead of automatically renewing.
Alternatively, you can purchase a gift code for the site and use it for yourself if you'd prefer. Head here to purchase a gift code: https://www.eatthismuch.com/app/account/subscription/send-gift