This spinach-and-feta breakfast casserole is a crowd-pleasing dish that makes a perfect centerpiece for your weekend brunch.

Fiber-rich whole-wheat English muffins add a heartiness to this dish that will leave you full and satisfied.

Keep reading for our expert tips, including ingredient substitutions and additions.

an image of the Spinach & Feta English Muffin Breakfast “Sandwich” Casserole

Photo:Photographer: Robby Lozano, Food Stylist: Emily Nabors Hall, Prop Stylist: Lydia Pursell

Light coat a 9-by-13-inch baking dish with cooking spray.

Heat 1 tablespoon oil in a large skillet over medium heat until shimmering.

Add chopped onion; cook, stirring occasionally, until softened and translucent, about 3 minutes.

an image of the ingredients to make the Spinach & Feta English Muffin Breakfast “Sandwich” Casserole

Photographer: Robby Lozano, Food Stylist: Emily Nabors Hall, Prop Stylist: Lydia Pursell

Transfer 12 cup of the spinach mixture to a medium bowl.

Pour the egg mixture into the prepared baking dish.

Cover the dish tightly with foil.

an image of the spinach, onion, sun-dried tomatoes, and garlic cooking in a skillet

Photographer: Robby Lozano, Food Stylist: Emily Nabors Hall, Prop Stylist: Lydia Pursell

Bake until the eggs are nearly set, about 25 minutes.

Remove the foil and sprinkle the remaining 14 cup feta between the muffins.

Bake until the eggs are fully set in the middle, 15 to 18 minutes.

the egg mixture being whisked next to the cream cheese and feta mixture

Photographer: Robby Lozano, Food Stylist: Emily Nabors Hall, Prop Stylist: Lydia Pursell

Let rest for 10 minutes before slicing and serving.

To make ahead

Prepare the casserole (through Step 5) up to 1 day in advance.

To reheat a whole casserole, place it in a 350F oven for about 20 minutes.

an image of the cream cheese and feta mixture being spread over the english muffins

Photographer: Robby Lozano, Food Stylist: Emily Nabors Hall, Prop Stylist: Lydia Pursell

If you are heating a single serving, microwave it on High in 30-second intervals until its warmed through.

you might freeze the cooked casserole.

Its like testing a cake: Stick a knife into the center of the casserole.

If it comes out clean without any ingredients clinging, the casserole is finished cooking.