In a mixing bowl, whisk together milk, all-purpose flour, eggs, and a pinch of salt. Allow the batter to rest for about 15 minutes.

Preheat a non-stick skillet over medium heat and lightly grease it. Pour a ladleful of the batter onto the skillet and cook for about 2 minutes until set. Flip and cook for an additional minute.

In a separate pan, heat olive oil over medium heat. Add spinach and sauté until wilted. Whisk eggs in a bowl, pour into the spinach pan, and cook until fluffy. Stir in cheddar cheese until melted.

Lay a cooked crepe flat and spoon a generous amount of filling onto one side. Fold over and then again to make a triangle or roll. Serve warm.