Step 1

Heat olive oil and butter in a 9-inch nonstick pan over medium heat and cook asparagus, stirring occasionally, until soft but still firm to the bite, 10 to 15 minutes.

Step 2

Beat eggs in a bowl until frothy. Stir in Parmesan cheese and milk; season with salt and pepper. Pour egg mixture over asparagus and cook until eggs are set, 10 to 15 minutes.

Step 3

Invert frittata onto a plate and garnish with parsley.