This experiment is rather simple. You need water, pepper, and dish soap. The water goes into the raised plate. Then add enough pepper to cover most of the surface. Put a drop of dish soap on your finger and poke the center of the water. Observe.
The pepper isn’t running away from the dish soap, but rather the water is moving away. The dish soap reduces the surface tension of the water in the middle of the plate. In order to stay afloat the pepper moves to the area with the highest surface tension.
Or you can just claim that it is magic and impress your house guests with your newly found trick!