Using a dry measuring cup, scoop 1 cup of brown rice into a fine-mesh basket strainer. Rinse the brown rice thoroughly with cold, running water. Brown rice is usually covered in a powdery starch, so it is important to give it a good rinse to avoid a gummy final product. When the water runoff turns from cloudy to clear, your brown rice has gone through sufficient rinsing. Set aside.
Using a wet measuring cup, add chicken stock to a medium saucepan. Stir in butter and gray salt. Bring stock to a boil over medium-high heat.
Add rinsed brown rice, stirring to combine. Return the mixture to a boil, then cover and reduce the heat to low. Simmer the brown rice until all of the liquid is absorbed (15 – 20 minutes). Remove from the heat and let sit covered for 2 minutes.
Finish by fluffing the brown rice with a fork.