Combine flour, salt, cream of tartar and Jell-O powder in a medium saucepan.
Add water and vegetable oil and stir until combined.
Cook on medium heat, stirring constantly, until the mixture becomes a ball of dough that no longer sticks to the sides of the wok. This should take no more than 5 minutes.
Set the play dough aside to cool. Once it’s cool enough, knead it with your hands until smooth. Then, give it to your child to play with!
Notes
Store play dough in a sealed zip-top bag when not in use.