Button HorizontalOptions not working inside stacklayout

Hi ,
Can any please explain how to align button to top in the Grid. Currently My xaml looks like
I cannot align horizontalOptions="start" for the buttons inside stacklayout, where as stacklayout is placed inside the grid. Please see the image for more understanding.

<TabbedPage.ItemTemplate>

<ListView.ItemTemplate>

 <Grid Padding="5" >
                <Grid.RowDefinitions>
                  <RowDefinition Height="30"></RowDefinition>
                  <RowDefinition Height="20"></RowDefinition>
                  <RowDefinition Height="50"></RowDefinition>

</Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                  <ColumnDefinition Width="100"></ColumnDefinition>
                  <ColumnDefinition Width="*"></ColumnDefinition>
                  <ColumnDefinition Width="40"></ColumnDefinition>
                </Grid.ColumnDefinitions>
                  <Image Grid.Row="0" Grid.Column="0" Grid.RowSpan="3"  Source="{Binding ThumbUrl}" HeightRequest="100" Aspect="AspectFill"/>
                  <Image Grid.Row="0" Grid.Column="2" Grid.RowSpan="3" HeightRequest="12"  Source="arrowright_16.png" HorizontalOptions="Center" />
                  <Label Grid.Row="0" BackgroundColor="Aqua" Grid.Column="1" Text="{Binding Name}" FontSize = "20"  LineBreakMode="TailTruncation"></Label>
                  <Label Grid.Row="1" BackgroundColor="Blue"  Grid.Column="1" FontSize = "15" Text="Price: $10.00" LineBreakMode="TailTruncation"></Label>

                 <StackLayout Grid.Row="2" HorizontalOptions="Start"  Grid.Column="1" Orientation="Horizontal" BackgroundColor="Blue">
                     <Label FontSize = "18" BackgroundColor="Aqua" Text="Add To Order" HorizontalOptions="Start"  LineBreakMode="TailTruncation"></Label>
                     <Button Text="+" BackgroundColor="Aqua"  WidthRequest="60" CommandParameter="{Binding Name}" Clicked="AddClicked" HorizontalOptions="Start" VerticalOptions="Start">    </Button>  
                     <Button Text="-"  BackgroundColor="Aqua" WidthRequest="60" CommandParameter="{Binding Name}" Clicked="RemoveClicked" HorizontalOptions="Start" VerticalOptions="Start">    </Button>  
                 </StackLayout>

              </Grid>
            </ViewCell>
          </DataTemplate>
        </ListView.ItemTemplate>
      </ListView>

    </StackLayout>
  </ContentPage>
</DataTemplate>

</TabbedPage.ItemTemplate>