public class Methods_to_List
{
   public string WFid { get; set; }
   public string Description { get; set; }
}

List<InterfaceManagement.Entities.Methods_to_List> cbLists = new List<InterfaceManagement.Entities.Methods_to_List>();

foreach (WorkFlowEngine.WorkFlow item in workFlows)
{
   cbLists.Add(new InterfaceManagement.Entities.Methods_to_List() { WFid = item.WFID, Description = item.Description.Trim().Length > 0 ? item.Description.Trim() : item.Name.Trim() });
}     

cbMasterWF.ItemsSource = cbLists;

---
<ComboBox Style="{StaticResource ComboBox}" Name="cbMasterWF" Grid.Column="1" Grid.Row="0" Grid.ColumnSpan="2" ItemsSource="{Binding}">
   <DataTemplate>
      <Grid ShowGridLines="True">
         <Grid.ColumnDefinitions>
            <ColumnDefinition Width="40"/>
            <ColumnDefinition Width="100"/>
         </Grid.ColumnDefinitions>
         <TextBlock Grid.Column="0" Text="{Binding WFid}" Style="{StaticResource TextBlock}"/>
         <TextBlock Grid.Column="1" Text="{Binding Description}" Style="{StaticResource TextBlock}"/>
      </Grid>
   </DataTemplate>
</ComboBox>
---