You'll just need to design the objects you're returning and make it something like this: 

[DataContract]
public class OrderPayload
{
    [DataMember(Name = "id")]
    public Guid Id { get; set; }
    [DataMember(Name = "Number")]
    public string Number { get; set; }
}
 
[DataContract]
public class AccountPayload
{
    [DataMember(Name = "name")]
    public string Name { get; set; }
    [DataMember(Name = "orders")]
    public List<OrderPayload> Orders { get; set; }
}

Then you populate that as needed in the webserivce. The AccountPayload is the top level of the objects, so that is what the method would return. You'd populate like this (obviously from some data you read from an ESQ etc): 

var account = new AccountPayload();
account.Name = "Some account";
 
account.Orders = new List<OrderPayload>();
account.Orders.Add(someOrder1);
account.Orders.Add(someOrder2);
 
// now return account

Hope this helps get you started in the right direction.

Ryan

Hello!

Additionally, you can read more about custom web services here.