Croissant Sausage Brunch Bake with Gruyère Tips, FAQ & printable recipe

Tips for success

To get the crispiest top, make sure the croissant pieces are not all submerged in the custard. Leave some exposed so they can toast in the oven. If you prefer a softer texture, press them down gently into the custard.

For a more indulgent version, use half-and-half instead of whole milk, or add an extra egg for a richer custard. The bake is forgiving, so feel free to adjust the seasoning to your taste—add a pinch of nutmeg or cayenne for warmth.

When caramelizing the leeks, be patient and cook them over low heat until they're deeply golden and sweet. This can take up to 15 minutes, but it's worth it. If you're short on time, you can use a store-bought caramelized onion jam, but the flavor won't be quite the same.

For a make-ahead option, assemble the entire dish the night before, cover, and refrigerate. In the morning, let it sit at room temperature for 30 minutes, then bake as directed, adding a few extra minutes if needed.

Variations

• Bacon and Cheddar: Replace the sausage with 8 slices of cooked, crumbled bacon and use sharp cheddar instead of Gruyère. Add a teaspoon of smoked paprika to the custard for a hint of smokiness.
• Vegetarian Mushroom: Omit the sausage and add 200g of sautéed mushrooms with thyme. Use a vegetarian-friendly cheese like Emmental or a sharp white cheddar. The mushrooms add an earthy depth that pairs well with the leeks.
• Spinach and Feta: Add 100g of chopped spinach (thawed and squeezed dry) to the leek mixture, and substitute crumbled feta for half of the Gruyère. The salty feta and spinach create a fresh, bright flavor.
• Ham and Swiss: Use 150g of diced ham instead of sausage, and swap the Gruyère for Swiss cheese. Add a tablespoon of chopped fresh chives to the custard for a subtle onion flavor.

Storage and make-ahead

Fridge

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in the microwave or oven until hot and crisp on top.

Freezer

Freeze the baked, cooled strata for up to 2 months. Thaw overnight in the refrigerator, then reheat in a 350°F (175°C) oven until warmed through.

Reheat

Reheat individual slices in the microwave for 1-2 minutes, or in a toaster oven at 350°F (175°C) for 5-7 minutes until hot and the top is crisp.

Store leftover croissant bake in an airtight container in the refrigerator for up to 3 days. To reheat, place individual portions in the microwave or in a 350°F (175°C) oven for 10-15 minutes, until warmed through.

The top may lose some crispness upon reheating, but the flavor remains delicious. For best results, reheat in a toaster oven or under the broiler for a few minutes to revive the crunch.

This bake can be assembled up to 24 hours in advance. Prepare the sausage, leeks, and custard, then layer everything in the baking dish as directed. Cover tightly with foil and refrigerate.

When ready to bake, let the dish sit at room temperature for 30 minutes, then bake as directed, adding 5-10 minutes to the baking time if needed. The custard will be fully absorbed, and the croissants will be even more flavorful.

Serving ideas

Serve this croissant bake warm, straight from the oven, as the centerpiece of a brunch spread. It pairs beautifully with a simple green salad dressed with lemon vinaigrette, or with fresh fruit and yogurt. For a more indulgent meal, add a side of crispy bacon or smoked salmon. The bake is rich and satisfying, so a little goes a long way—cut it into generous squares and let guests help themselves.

For a festive occasion, top each serving with a sprinkle of fresh chives or parsley, and perhaps a dollop of crème fraîche. The creamy tang of crème fraîche cuts through the richness of the cheese and sausage. If you have leftover bake, it makes a great lunch the next day, served cold or reheated. The flavors meld even more overnight, so leftovers are often even better.

Frequently asked questions

Recipe card

Croissant Sausage Brunch Bake with Gruyère

Prep 20 minCook 28 minRest 10 minTotal 58 minServes 6

Ingredients

• 5 torn butter croissants
• 200 g browned sage pork sausage
• 100 g butter-caramelized leeks
• 120 g shredded Gruyère cheese
• 6 large eggs
• 300 ml whole milk
• 10 g Dijon mustard

Instructions

1. Heat a large skillet over medium heat. Add the sage pork sausage and cook, breaking it into small pieces, until browned and cooked through, about 8 minutes. Transfer to a plate. In the same skillet, melt a tablespoon of butter and add the sliced leeks. Cook slowly, stirring occasionally, until soft and caramelized, about 10 minutes. Set aside.
2. Tear the croissants into bite-size pieces and spread them evenly in a buttered 9x13-inch baking dish. Scatter the browned sausage and caramelized leeks over the croissants, then sprinkle with half of the shredded Gruyère.
3. In a large bowl, whisk together the eggs, whole milk, and Dijon mustard until completely smooth and well combined. Season with a pinch of salt and black pepper.
4. Pour the custard evenly over the croissant mixture, making sure all pieces are soaked. Sprinkle the remaining Gruyère over the top. Let the dish sit at room temperature for 10 minutes so the croissants absorb the custard.
5. Preheat the oven to 185°C (365°F). Bake the strata for 28 minutes, or until the top is deeply golden and the custard is set. The internal temperature of the eggs should reach 160°F (71°C).
6. Remove the bake from the oven and let it rest for 5 minutes before serving. This allows the custard to settle and makes slicing easier. Serve warm, with extra Gruyère if desired.

Contains: gluten, eggs, milk, mustard

Estimated nutrition per serving

Calories

520

Protein

24 g

Carbohydrates

30 g

Fat

33 g

Automatic estimate from the ingredient list, not laboratory-verified.