Step 4: Assemble the Casserole
Arrange the roasted asparagus in the prepared baking dish in a single layer (or slightly overlapping if needed).
Pour the cheese sauce evenly over the asparagus, ensuring all spears are coated.
If you want extra cheesiness (and why wouldn’t you?), sprinkle an additional ½ cup cheddar over the top.
Step 5: Make the Topping
In a small bowl, combine panko, Parmesan, melted butter, parsley, and lemon zest (if using). Mix until the crumbs are evenly moistened.
Sprinkle the topping evenly over the casserole.
