Header text intersecting a border around an element

I've used double nested frames to mock up something that looks like a border but I can't figure out a way to have some text intersection that border like this: https://imgur.com/a/Q313H. I've tried negative margins but that just made the text disappear entirely. How can this be done?

This is what I currently have:

<Frame CornerRadius="4" HasShadow="False" OutlineColor="Gray" Padding="3" Margin="0,0,0,0" BackgroundColor="#CCCCCC">
                    <Frame CornerRadius="4" HasShadow="False" OutlineColor="Gray" Padding="10" Margin="0" BackgroundColor="White">
                        <StackLayout Margin="0, 0, 0, 40" HorizontalOptions="FillAndExpand" VerticalOptions="Fill">
                            <StackLayout Orientation="Horizontal" Margin="0,0,0,0">
                                <Image Source="comments.png" WidthRequest="19" HeightRequest="19" />
                                <Label Text="Comments" Font="Bold,20" HorizontalOptions="FillAndExpand"/>
                            </StackLayout>
                            <ListView x:Name="commentsListView">
                                <ListView.ItemTemplate>
                                    <DataTemplate>
                                        <ViewCell>
                                            <StackLayout Orientation="Horizontal">
                                                <Label x:Name="commentComment" Text="{Binding comment}" FontSize="15" HorizontalOptions="FillAndExpand"/>
                                                <Label x:Name="commentName" Text="{Binding name}" FontSize="15" HorizontalOptions="FillAndExpand"/>
                                                <Label x:Name="commentDate" Text="{Binding comment_create_date}" FontSize="15" HorizontalOptions="FillAndExpand"/>
                                            </StackLayout>
                                        </ViewCell>
                                    </DataTemplate>
                                </ListView.ItemTemplate>
                            </ListView>
                            <Label Text="There are no comments``" x:Name="commentsMessage" />
                        </StackLayout>
                    </Frame>
                </Frame>