To create this widget you need to select Custom widget (last widget in dropdown add widget menu)
Segment: Organic Traffic
Dimension : Month of the Year (for example)
Metric: goal Completions All
You can choose to track all goals completion.
Or you can choose to track organic traffic for specific goals:
In step 2, you can edit widget title, widget description, and select data to hide.
During the last step you can choose the format and size of your GA widget.