Kitchen sinks can get blocked quite easily as waste food can build up by the drain.
Instead of having one drainage hole, having multiple or a larger drainage area would allow the water to drain quicker and reduce the chance of a blockage. One possible drainage method would be to have a gap between the base and sides of the sink. This would mean that the middle of the sink is raised slightly and the water can run off in any direction. There can also be another drainage gap further up the sides of the sink to prevent it overflowing.
To block the drainage, it can be as simple as pushing the centre of the base of the sink and allowing it to flatten. To allow drainage again, it would just involve pulling the centre of the sink back up slightly.
As always, if you think you have a solution or if you have a problem you would like me to try to solve then please feel free to comment it.