Adobe
Photoshop Tutorial:
Here is a really quick way to make a background using the paint brush and Polar Coordinates.
Step 1: Start with a new layer above the background layer. Select the paint brush tool and pick a favorite color to paint with. Set the edge to be soft like around 20 or so and start painting straight lines from one end to the other. If you hold down the shift key while painting it makes straight lines.
Step 2: Go to the menu Filter->Distort->Polar Coordinates and select Rectangular to Polar.
Step 3: Next I faded the layer 50% and added some food to complete the image.
