It's an easy job. Create the outer polygon and the make it transparent going to the symbol ogo tab. Create the inner polygon where you want the lake like feature. Select the inner polygon and use clip geoprocessing tool. There will be option to remove the touching polygon area. Or else delete both the inner polygon and the clip created.
Maybe there's a problem with my expression，there is only one feature in my picture. So once i choose, i choose it all, i can't choose the outer polygon.So called inner polygon is empty, i can't choose it.
