BUCKWHEAT CREPES WITH ASPARAGUS, HAM AND GRUYèRE

Steps:

• Make the batter: Whisk together flours, eggs, buttermilk and salt until well combined. Put the batter in the fridge for at least 2 hours or, preferably, overnight. If necessary, thin batter with a little more buttermilk or water, to the consistency of heavy cream.
• Heat a crepe pan or well-seasoned cast iron skillet, about 8 inches in diameter, over medium-high heat. Use a piece of paper towel to rub a little butter in the pan, then quickly ladle in about 1/4 cup of batter. Swirl the pan to spread the batter all the way to the perimeter. Let crepe brown on one side for a minute or so, until crisp. Flip it over with a spatula (or carefully with your fingers) and cook one minute more. Don't worry about browning the second side. Adjust heat if crepe browns too quickly; the pan needn't be scorching hot. Remove from heat if crepe is cooking too quickly.
• Remove the crepe from the pan and set it aside while you continue to make 5 more. Stack crepes on top of each other as they are finished. (Crepes may be made in advance.)
• Bring a medium pot of generously salted water to a boil. Cook the asparagus for 2 minutes, or just until it is firm-tender, then drain and spread on a clean kitchen towel to cool.
• Heat oven to 400 degrees. Fill the crepes by laying each one top-side down, place a slice of ham on top, sprinkle generously with cheese, and lay 3 asparagus spears on top, off to one side. Fold over to make a half-moon.
• Put the filled crepes in one layer on a baking sheet. Drizzle with a little melted butter, then bake until they are crisp and the cheese is melted, about 5 to 7 minutes. Serve immediately.