In a medium bowl, whisk together milk and eggs. Add flour and salt; mix until very smooth. Cover and refrigerate for at least half an hour.
Heat a fry pan over medium heat. Add butter and swirl in to coat entire pan. Ladle about 2 oz. of batter into center of pan; move pan around to quickly spread batter.
Cook until edges of crepe look cooked, then carefully turn over with a spatula or flip in pan. Briefly cook the other side. Remove crepe; return pan to stovetop and repeat process with remaining batter.
Fill with your favorite savory filling and roll or fold into quarters.