How to Make It
In a blender, combine the flour, salt, milk, water, eggs, and 1 tablespoon of the melted butter. Pulse for 10 seconds until smooth. Cover and place the crêpe batter in the refrigerator to let rest for 20 minutes.
Preheat the oven to 350°. Heat a 10-inch nonstick pan and lightly brush it with some of the remaining butter. For each crêpe, add 1/4 cup of the batter to the pan and quickly swirl to spread evenly. Cook over moderate heat until the underside is speckled and lightly golden, about 30 seconds to 1 minute. Flip the crêpe and cook for 30 seconds to 1 minute longer. Transfer to a baking sheet; repeat with the remaining batter to make 10 crêpes, brushing the pan with butter as needed.
Fold the crêpes into quarters and arrange on the sheet tray and bake until hot, about 4 minutes. Place the crêpes on plates or a large serving platter. Spoon the mascarpone over the top, pour over the strawberries, and serve right away.