Using EnsureUser with ADFS

I am trying to take some users and author them to list item posts. The SPWeb.EnsureUser() method works fine on a server only utilizing AD, but not one that is using ADFS.

Here is my attempt at checking users against ADFS.

//<Claim>|<Claim Issuer>|<Value>SPUser user = web.EnsureUser("i:05.t|myIssuer|someone@domain.com");

Please keep in mind that someone@domain.com exists in AD, but has not necessarily logged into SharePoint.

Is this of correct format? Is there somewhere I can pull <Claim> and <Claim Issuer> so I can ensure I am using the correct providers?