| 1 pound | Asparagus |
| 2 tablespoons | Butter |
| ½ cup | Milk |
| 3 large eggs, at | Room temperature |
| ½ cup | Flour |
| | Salt and pepper |
| | Pinch sugar |
| 3 ounces | Gruyere or Swiss cheese, shredded (1 cup loosely packed) |
1. Position a rack in the lower third of the oven and preheat to 425 degrees. In a medium saucepan, add enough salted water to reach a depth of 2 inches; bring to a boil. Add the asparagus and cook until crisp-tender, about 3 minutes. Drain and rinse with cold water, then pat dry with paper towels. Cut the spears crosswise into thirds.
2. In a medium cast-iron skillet, add the butter. Place the skillet in the oven to melt the butter.
3. In a medium bowl, microwave the milk on high for about 30 seconds. Whisk in the eggs, then the flour, ½ teaspoon salt, ½ teaspoon pepper and the sugar.
4. Add the asparagus pieces to the hot cast-iron skillet and pour the batter on top. Sprinkle with half of the cheese and bake until puffed golden-brown, 18 to 20 minutes. Top with the remaining cheese.