Make crepe batter by placing eggs, salt, flour, and milk in a blender. Blend until smooth.
Heat a nonstick skillet over medium heat. Lightly grease the pan. Pour a little of the crepe batter in the pan and swirl it around to cover the bottom of the pan. Let cook about 1 minute, until surface loses its shine. Flip carefully. (see video for demonstration). Repeat until all batter has been used.
Preheat oven to 400 degrees. Lightly grease a 9x13 pan.
Make the filling by combining the sour cream, mushrooms, olives, green onion, celery, chicken, and half the cheddar cheese in a mixing bowl. Place a heaping spoonful in the center of each crepe. Fold ends and sides over and place in prepared pan.
Bake 20 minutes at 400°. Remove from oven and sprinkle on 1 cup grated cheese. Bake another 10 minutes until cheese is melted.