In a small pot, bring water and oats to a boil. add salt, reduce heat, and simmer for 20-25 minutes until thick and creamy, stirring often.
Stir in butter if using. Spoon into a bowl and add your favorite toppings (see notes for topping ideas).
Notes
For creamier, thinner oats, add more water.
To add flavor: sauté fresh-grated ginger or minced garlic in the pot before adding water and oats, or stir in miso paste (about 1 teaspoon) or turmeric at the end.