Buttery Croissant and Prosciutto Breakfast Strata Step-by-step instructions

Before you start

Before you begin, ensure your workspace is clear and your ingredients are prepped. Trim the asparagus spears into uniform, bite-sized pieces to ensure they cook evenly. Shred the Fontina cheese and grate the Parmigiano fresh to guarantee the best melt.

Tear the prosciutto into ribbons, as this helps it distribute throughout the layers rather than clumping together. Having everything ready to go makes the layering process seamless, allowing you to focus on the assembly and ensuring the custard is whisked to perfection before adding it to the slow cooker.

Instructions

Layering the ingredients

1. 1Prepare the layers
   Begin by tearing the six day-old butter croissants into rough, bite-sized chunks. In your ceramic slow cooker insert, start building the base by arranging a portion of the torn croissants, followed by a layer of prosciutto ribbons, fresh asparagus spears, shredded Fontina, and grated Parmigiano. Continue alternating these layers until all components are used, ensuring an even distribution of the ingredients throughout the vessel to create a cohesive structure for the final bake.
   Look for Ensure the ingredients are layered evenly to prevent pockets of dry croissant or unseasoned cheese.
   Tip Using day-old croissants is ideal because they are slightly firmer and hold their structure better when soaked in the egg custard.

The slow cooker insert should look vibrant and full, with the croissant chunks, asparagus, and prosciutto distributed in clear, distinct layers. You should see the cheese nestled between the bread and vegetable pieces, promising a delicious melt once the heat begins to penetrate the strata.

Ensure the layers are not packed too tightly, as this allows the egg mixture to flow downward and coat every single component evenly, which is the key to a uniform and flavorful breakfast casserole.

Whisking the custard

2. 2Whisk the custard
   In a medium mixing bowl, combine the eight large eggs with the cup of gruyere cream and the tablespoon of Dijon mustard. Whisk the mixture vigorously until the eggs are completely broken down and the cream is fully incorporated, resulting in a smooth, uniform liquid. Pour this custard mixture evenly over the layered ingredients in the slow cooker, making sure to coat the croissant pieces thoroughly so they absorb the liquid for a rich, custardy finished texture.
   Look for The mixture should be completely homogeneous with no streaks of egg white remaining.
   Tip Whisking thoroughly ensures the custard sets evenly throughout the strata, preventing any loose or watery sections after the long cooking time.

The custard should be a smooth, pale yellow liquid with a consistent texture throughout. There should be no visible lumps of Dijon mustard or unmixed cream. When poured over the layers, the liquid should seep down gradually, filling the gaps between the croissants and vegetables.

It is important that the custard is poured slowly and evenly across the entire surface to ensure that every corner of the strata is adequately moistened, which guarantees a consistent and delicious result.

Slow cooking to completion

3. 3Slow cook and serve
   Place a clean kitchen towel under the slow cooker lid before securing it. This simple trick absorbs excess condensation, preventing moisture from dripping back onto the strata and ensuring the top croissant peaks remain crisp while the bottom base becomes perfectly custardy. Set the slow cooker to LOW and cook for three hours. To ensure the eggs are fully cooked through, verify the internal temperature of the egg custard reaches 160°F (71°C). Serve warm, garnished with fresh thyme and lemon zest.
   Look for The strata should be golden brown on top, puffed, and set in the center.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip The kitchen towel is essential for maintaining a crisp texture on the exposed croissant edges.

The strata should appear puffed and golden on top, with the croissant peaks looking crispy and toasted. The cheese should be melted and slightly browned in spots, and the asparagus should be tender when tested with a fork. The kitchen towel under the lid will be damp, indicating it has successfully trapped the excess moisture. The entire dish should be firm to the touch, and the aroma should be savory and inviting, filling the kitchen with the scent of toasted pastry.

Common mistakes

Avoid over-crowding the slow cooker, as this can prevent the custard from circulating properly and lead to uneven cooking. Another common mistake is using fresh, soft croissants; if they are too moist, they will become soggy rather than custardy.

Ensure the kitchen towel is placed securely so it does not obstruct the lid's seal, but do not let it touch the heating elements. Finally, do not rush the cooking time; the three-hour duration is necessary for the flavors to meld and the custard to set properly.

How to tell it’s done

To determine if the strata is done, look for a golden-brown, puffed surface that has pulled slightly away from the edges of the ceramic insert. The center should be set, with no visible liquid egg remaining when you gently press the surface with a spoon. Use a digital probe thermometer to check the center of the strata; it must reach an internal temperature of 160°F (71°C) to ensure the eggs are fully cooked and safe to consume. Let it rest for ten minutes before serving.

• Egg dishes: 160°F (71°C) in the thickest part