In a small saucepan, heat the milk to a boiling point over medium high heat. Turn off the heat, add the shredded cheese and whisk until the cheese is fully melted.
Transfer the cheese mixture into a mixing bowl with whisk attachment. (Alternatively, you can use a handheld electric mixer or just whisk.) Whisk the mixture on low speed until it’s cooled down to room temperature. (Make sure the mixture is not hot before adding the eggs, or you’ll get scrambled eggs.) Add the eggs and beat the mixture until well combined, about 3 minutes. Add the flour, sugar and salt and beat on medium low speed just until combined, 1-2 minutes. Don’t overmix, or the batter will get tough and rubbery! Whisk in the vegetable oil.
Heat 10-inch non-stick skillet over medium high heat. (The bottom of my 10-inch pan measures 7 inches, which means the crepes will be 7-inch round.) Place a little less than ¼ cup of batter into the hot pan, quickly swirl the pan so the batter is evenly covers the bottom of the pan. In about 1 minute, when the edges of the crepe start to pull away, flip it over using a spatula. Cook for about 30 seconds or so and stack the crepes on a plate. You’ll get about 16 crepes. Cool the crepes completely. At this point you can wrap the crepes with a plastic wrap and refrigerate for up to a day.
To make the filling, mix the sour cream with chopped scallion. Salt and pepper to taste. When ready to serve the crepes, spread about ½ tablespoon of filling all over the crepes. Fold in two sides, and then roll the crepe into a cigar.