In a large mixing bowl, whisk together the flour and the eggs. Gradually add in the milk and water, stirring to combine. Add the salt and butter; beat until smooth.
Heat a lightly oiled frying pan over medium high heat. Pour or scoop of the batter onto the pan, using approximately 1/4 cup for each crepe. Tilt the pan with a circular motion so that the batter coats the surface evenly. Cook the crepe for about 2 minutes, until the bottom is light brown. Loosen with a spatula, turn and cook the other side.
Melt butter in a small pan. Remove pan from heat and add flour, salt and pepper. Stir until smooth. Stirring constantly, add milk slowly. Return to a medium heat bring to a boil, stirring constantly. Simmer for 1 minute. Add cheese and stir over low heat until melted. Remove from heat.
Drain spinach. In 10″ greased pan melt butter and sauté spinach for 2 minutes. Remove from heat. Reserve 1/2 cup cheese sauce. Combine the rest with the spinach and mix well.
Preheat oven to 350 degrees. Using aprox. a 1/2 cup of filling for each, assemble crepes on a buttered heat proof dish. Heat for 10 minutes and serve. Garnish with a fresh sprig of basil.