Put the dry ingredients in a medium saucepan and whisk to combine.
Add the water and oil, and stir together.
Cook on medium heat for 3-5 minutes, stirring constantly, until the dough comes away from the sides of the pan and forms a ball in the center, a silicone spoon works really well for this. It will look lumpy, but don't worry.
Turn the warm dough out onto a lightly floured surface and gently knead it a few times until it is smooth and not sticky. Lightly flour your hands if necessary.
Store the playdough in an airtight baggie or container.