In a child safe bowl, mix the corn flour with water and food colouring and you're ready to play!
If you poke it with your finger on top of the goop quickly it is hard. If you do this slowly your fingers falls into the goop. You can grab a handful and drop it only your hands and it looks like its melting. It's so much fun and so super easy to clean up. You can either hose it down, or leave it to dry and sweep it off.