Combine salt, flour, water, cream of tartar, and cooking oil in a large, heavy skillet.

Add food coloring, if desired.

Cook over low heat, stirring continuously, until the mixture becomes stiff and cleans the pan like pie dough.

Remove from heat.

Beat the dough to cool it down.

Knead the dough like bread until it becomes pliable.

Store in an airtight bag or container.

If the dough becomes sticky, work in flour until the stickiness disappears.