I wish it was as simple as that. :) I spent all of Christmas Eve and Christmas day trying to figure out how to make these bowls. I went through 30+ pounds of clay and made 7 or 8 of these. The difficult part was making a clean piece with the bowl portion having a clean edge.
In the picture below you can see the progression of the last five from left to right. For the first piece, I cut the hole in the pillow shape and took a bigger slab of clay to slump it in. The edges of the pillow collapsed and after a lot of fussing finished it but I wasn't happy. The next one I tried a different shape cut out to make it easier to slump the clay in and that was not as clean as I wanted.
In the third I used the cut out itself, flipped it over and atached it. It attached fairly cleanly but had no volume. It would be a bowl that held nothing. Which made me think that the piece of clay being slumped needs to be a perfect match in dimension.
So that is what I did. I took precise measurement of the cut out. Increased it by 1/2 inch all around and it slumped and fit in a lot better.
Making anything new is a process, but it is a process I enjoy. Never fear to experiment and see what direction it can take you. In the picture below you can see how the edges got cleaner with every piece.
I did toss out the first three pieces too and decorated just the final two with my signature slip decoration. That just gave them the WOW factor!