Knead a plum-size piece of terra-cotta-colored air-dry clay and pea-size bits of white and gray (mixed from black and white) air-dry clay together to create a swirled effect.
Using a rolling pin, flatten into a 1/4-inch-thick disk. Punch out a circle with a round cookie cutter or drinking glass and cut a wedge out of it.
Bring the edges up, overlapping and smoothing them together. Press the bottom of the bowl down onto a flat surface to flatten it, and let dry.