What the term describing cooking certain foods slowly with a little water in covered pot?

The term you're looking for is braising.

Braising involves:

* Sealing: Searing the food in a hot pan to develop a crust and flavor.

* Slow Cooking: Cooking the food in a covered pot with a small amount of liquid over low heat for a long period of time.

This method is perfect for tougher cuts of meat, vegetables, and other ingredients that benefit from long, slow cooking.