Bring water to boil in a medium-sized saucepan. Add salt, oats, optional coriander or cardamom, and optional apple, give it a stir, lower heat to a simmer, and cook for a couple minutes.
Turn off the heat, give oats a stir, and cover the pan. Let sit for 5–15 minutes, depending on how much time you have and how firm or soft you like your oatmeal. Sweeten as you like and add toppings.