1 Crack eggs into a blender container. Add milk, 1 cup cold water and salt. Blend to mix. Add flour and butter. Blend 1 minute, scraping down sides of container if necessary. Cover; refrigerate 2 hours or up to 24. (Leave in the blender container if desired.).
2 Heat an 8-inch well-seasoned crepe pan or nonstick skillet over medium-high heat until hot. Dip a paper towel into a little vegetable oil; carefully wipe it over the inside of the hot pan. Set the pan over the heat to heat the oil. Pour in a generous 2 tablespoons batter. Immediately pick up the pan and swirl it gently to coat the entire bottom evenly with the batter. Pour any batter that does not adhere to the pan back into the container of batter. Return the pan to the heat; cook until set, light brown and little beads of moisture are visible on the surface, about 30 seconds. Use a heatproof spatula to help loosen and flip the crepe. Cook the second side to brown it lightly, about 30 seconds more.
3 Transfer the cooked crepe to a covered baking dish. Keep warm in a low oven while you cook the remaining crepes. Top each crepe with a couple of tablespoons of the desired filling. If using the Florentine filling, roll up the filled crepes and serve sprinkled with chopped parsley.
Florentine: Heat 1 tablespoon olive oil in a large nonstick skillet. Add 1 halved, thinly sliced onion; saute until golden, 5 minutes. Add 2 cups chopped mushroom caps; cook until golden, 4 minutes. Stir in 2 bags (6 ounces each) spinach and 2 finely chopped cloves garlic (add spinach in batches if needed). Cook and stir until the spinach just barely wilts, about 3 minutes. Transfer to a plate to cool. Stir in 4 ounces crumbled goat cheese, and salt and pepper.
Jam and creme fraiche: Spread hot crepe lightly with a scant tablespoon of creme fraiche. Top with dollops of your favorite jam; smooth with a rubber spatula. Fold crepe into quarters. Sprinkle with confectioners' sugar.
Caramel and banana: Spread hot crepe lightly with a scant tablespoon of caramel sauce or Mexican cajeta. Top with sliced bananas. Fold crepe into quarters. Top with more caramel and banana slices and sprinkling of confectioners' sugar.