In a pot, bring the milk to a boil, but do not let it scorch.
Add the vinegar.
Let the mixture separate completely, a few seconds.
Strain the mixture through a cheesecloth.
Twist the cheesecloth to squeeze out the liquid.
Set the cloth on a flat surface and weigh down with a large saucepan filled with water to the top.
Let sit until all the liquid is gone and a firm cake is formed, 1 to 1-1/2 hours.
Cut the cake into 1-inch cubes.
In a pan, lightly saute the cubes in vegetable oil.
Makes enough for 2 recipes.
NOTE: The unused portion may be wrapped tightly in foil and plastic and frozen.
Thaw before using.