World's Best Playdough Recipe

This recipe was given to me at a playgroup a good 7 years ago, and it was named the "World's best playdough", and it is a great recipe. I think because it is cooked, it lasts forever as long as it is put away as soon as the children have finished playing with it and stored in an airtight container. It also has a lovely pliable feel to it because of the added cream of tartar.

2 cups white flour
1/2 cup salt
4 Tbsp cream of tartar
2 cups of water
2 Tbsp oil
4tsp food colouring (or add to achieve the desired colour)

Mix flour, salt, and cream of tartar in a pot. Add water, oil and food colouring. Cook and stir over medium heat. When the mixture forms a ball in the pot, turn out and knead on a lightly-floured surface. Store in an air-tight container.
It looks really liquid to start and hard to imagine it is going to turn into playdough, but keep stirring on medium heat.
We sometimes add glitter and flavourings like banana for yellow playdough and strawberry for pink.

This is what the end product should look like.