Melt butter in a medium-sized pot over medium-high heat until lightly browned (be sure to keep a close eye on it, so it doesn't burn).
Stir in the water, trahana, and a pinch of salt.
Bring to a boil, then reduce the heat to low and simmer for fifteen minutes, stirring occasionally to prevent the trahana from sticking to the bottom. The trahana will absorb a lot of the water and will be soft. (See notes)
Add the milk and feta and cook for an additional five minutes, stirring occasionally.
Remove from heat and let rest for five minutes.
Taste and add more salt if necessary. (See notes)
Serve with crusty bread and enjoy!