Savory Buckwheat Crepes

Name: Savory Buckwheat Crepes
Ingredients: For the crepe batter; 1/2 cup buckwheat flour; 2/3 cup whole milk; 2 large eggs; 1 tablespoon butter, melted; 1/2 teaspoon salt; For the filling; 2 tablespoons olive oil, divided; Kosher salt; 1 pound chicken thighs; 1 large red onion, thinly sliced; 2 garlic cloves, minced; 1 bunch asparagus, end trimmed, cut on the bias into 1/2 inch pieces; 2 cups gruyere cheese, shredded; 1 tablespoon butter, for greasing the pan; 2 scallions, chopped, as garnish