Introduction

This Egg and Croissant Brunch Bake is a comforting and flavorful dish perfect for weekend mornings. Combining caramelized onions, savory ham, fresh spinach, and melty cheese, it’s a hearty bake that feels both indulgent and homey. Plus, the croissant pieces on top add a buttery, flaky texture that makes every bite special.

A rectangular white baking dish filled with a golden brown baked casserole cut into a grid of square pieces, featuring a top layer of melted cheese that is bubbly and slightly browned in spots. The cheese layer shows gooey, stretchy textures with a mix of creamy white and golden yellow colors. Small green chopped chives are sprinkled evenly across the top, adding a fresh pop of color. Underneath the cheese layer, the casserole appears to have a soft, slightly uneven texture with hints of light yellow and white, suggesting layers of eggs or a similar base. The dish rests on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 tablespoons olive oil

1 large yellow onion, sliced thinly

2 1/2 cups diced ham

2-3 ounces fresh baby spinach

1 cup shredded cheese (Swiss/Gruyere mix recommended)

12 eggs

1/2 cup milk

1 tablespoon Dijon mustard

1 teaspoon salt

Pepper to taste

5-6 mini croissants, torn into small pieces (or 3-4 large croissants)

Instructions

Step 1: Heat the olive oil over medium-low heat in a large heavy pan. Add the sliced onions and cook, stirring occasionally, for about 30 minutes until they turn a deep golden brown and become almost jammy in texture.

Step 2: In a separate skillet, toss the diced ham with a drizzle of olive oil and pan-fry until the edges are browned and some fat is rendered. Add the fresh baby spinach, stir to wilt, then remove from heat.

Step 3: In a large bowl, whisk together the eggs, milk, Dijon mustard, salt, and pepper until well combined.

Step 4: Preheat the oven to 350°F (175°C) and grease a 9×13-inch baking dish. Layer the ham, spinach, and caramelized onions evenly on the bottom of the dish. Sprinkle half of the shredded cheese over the top.

Step 5: Pour the egg mixture over the layered ingredients. Arrange the torn croissant pieces on top and finish by sprinkling the remaining cheese over everything.

Step 6: Cover the dish with foil and bake for 30 minutes. Then, remove the foil and bake for an additional 5-10 minutes until the eggs are almost completely firm and the bake has puffed slightly. Avoid overcooking to keep the texture creamy.

Step 7: Let it cool for a few minutes, then slice and serve warm. Enjoy your delicious brunch!

Tips & Variations

Use day-old croissants for better texture as they hold up well during baking without getting soggy.

Swap the ham for cooked sausage or bacon for a different protein flavor.

Add herbs like thyme or chives for extra freshness and aroma.

Try mixing in mushrooms or bell peppers with the spinach for added veggies.

FAQs

Can I prepare this the night before?

Yes, you can assemble the bake the night before and keep it covered in the refrigerator. Bake it fresh in the morning, adding a few extra minutes to the cooking time if it’s chilled.

What type of cheese works best?

Swiss and Gruyere cheeses are recommended for their nutty and creamy flavors, but you can use any melty cheese like cheddar, mozzarella, or fontina based on your preference.