This photo was taken on my out-of-date phone so apologies for the quality.
As you can see, the background has been filled in behind and back of the tureen and onions. I can now get an idea of the contrast between the subject and the background, and I am satisfied that the neutral greys that mainly compose the porcelain are adequate to express its white material.
I am almost tempted to leave it unfinished, with just the hint of a sketch in the foreground where the reflections will go. But that is a little contrived, so I'll soldier on - after Chrismas!