[SqlFunction(
   DataAccess = DataAccessKind.Read,
   FillRowMethodName = "List_FillRow",
   TableDefinition = "Date datetime, Quantity int")]
public static IEnumerable ListCount(...)
{
  using (SqlConnection con = new SqlConnection(connectionStringToSERVER2))
  { ... }
  return list;
}

CREATE PROCEDURE [dbo].[sp_Reports_NumaraSpalariJetWash]
BEGIN
    DECLARE curs CURSOR
    LOCAL STATIC READ_ONLY FORWARD_ONLY
    FOR

    SELECT ...

    OPEN curs

    FETCH NEXT FROM curs
    INTO ...;

    WHILE @@FETCH_STATUS = 0
    BEGIN

        INSERT INTO ...
                    (...)
        SELECT Date, Quantity
        FROM            dbo.ListCount(...)

        FETCH NEXT FROM curs
        INTO ...;
    END
END