I made these 2 fruit bowls back in December 2008 by welding washers together.
This one was formed over a piece of aluminum that was originally intended to be a reflector for a ceiling light. It had a nice curve to it, which became the shape of this flat-ish dish.
For this rounded bowl, I used a small spherical section of aluminum, apparently waste that had been melted down and poured into a small rounded mold.
It came out nicely, and very even.