Step 1

Preheat oven to 375ºF. Press pie crust into bottom and up sides of a 9-inch, removable-bottom tart pan or a 9-inch pie pan; refrigerate until ready to use.

Step 2

To make filling, heat oil in a small skillet over medium heat. Add onion and sauté until soft, about 3 minutes. Transfer onion to a large bowl and add ricotta cheese, cheddar cheese, egg, egg whites, mustard, oregano, salt and pepper; mix well and fold in broccoli. Spoon mixture into prepared crust and level surface with a wooden spoon; sprinkle with Parmesan cheese.

Step 3

Bake until a knife inserted near centre comes out clean, about 35 to 40 minutes. Let stand 10 minutes before slicing into 8 pieces.

Step 4

Yields 1 piece per serving.