1. Start by creating a new RGB image. I used the dimensions of 288 x 288 in the example. Create a new layer. Choose any two colors; foreground and background.

Click on Filter > Render > Clouds

2. Click on Filter > Distort > Pinch

Set the pinch value to 100%.
Negative value wont give that burst look, but result in something totally opposite. Give it a try ;)

3. Press Ctrl + F, a few times depending on how much burst you want in your image.

Ctrl + F ; is a hot key for reapplying the filter last used.

You should have something that looks like the image on the left.

4. For the lighting effect, click on Filter > Render > Lighting Effects and set the values to your choice.