I didn't cover my bowl Chookie, couldn't see any reason to do it.
Janetski, question is fine. Cover both. you can cover the dish with foil, just a bit more difficult to remove to stir. I love steaming so when I got the TMX, I put the Varoma in a bag and went to the local shopping center and tried lots of pyrex dishes to see what would fit. When I cook in the Varoma, the dish that i use, I take to the table and each person serves them selves. Hope this helps.