Heat the milk in a heavy-bottomed pot until frothy.  Be careful not to boil or it might spill out of the pot.  Stir occasionally to prevent burning/sticking on the bottom.

When milk is just about to boil, add the lemon juice and stir for about 30 seconds.  You should see the cheese curds form almost immediately.  You can let the liquid cool for up to an hour if you like, or pour directly through cheese cloth or a strainer to separate curds from the whey.  Wash the curds gently to remove any residual lemon juice.

Take the curds and wrap them in cheese cloth or other thin material and press firmly in a circular container for about an hour.  Make sure the liquid being pressed out can drain.  I like to use a bicycle inner tube as a giant rubber band to push a jar down onto the cheese, but any constant pressure (like a heavy book) will work fine.

After an hour, unwrap the cheese and cut into small (1/2 inch) cubes.  You can lightly salt the cubes if you like before putting in the fridge.  Cheese will keep for a few days.  Throw into a dish near the end of the cooking period to retain texture, while still allowing the cheese to absorb the flavors of the dish.

Enjoy!