why it works
- Using fine-kneed white bread, instead of more open-structured artisan bread, allows for better absorption and retention of the custard.
- Bread that has been dried in a low oven is more absorbent than stale bread.
- A low temperature oven of 325°F (160°C) gently cooks the pastry cream.
- Covering the strata with aluminum foil for part of the cooking prevents the surface from drying out.
For those unfamiliar with strata, it’s basically a breakfast casserole reminiscent of a salty bread pudding or egg stuffing. Built on a base of bread, eggs and cheese, enhanced with milk and cream, and topped off with an endless combination of toppings, in this case, which includes crispy bacon and tender kale. All the work can be done the night before, so all you have to do is put it in the oven when you wake up.
Ideal strata should be creamy, not rubbery, and easy to cut into neat portions, with a slightly crispy top. Strata is made up of layers, as the name suggests (“strata” is a geological term that refers to layers of rock or soil), which ensures that the ingredients are evenly dispersed, much like a lasagna.
In theory, you can use any type of bread: I tested with crispy baguette, sourdough, and even rye. None of these were particularly disappointing, but the big winner was supermarket-style “French” or “Italian” bread. Finer hole structure, thin crust, and soft, chewy texture improve absorption and retention of flavorful custard. Another good option is a quality white sandwich loaf, but I don’t recommend the brioche, which is a little too rich considering the other ingredients in the dish.
In order to create a custardy layer, the bread really has to be one with the custard. A beautiful layer combines the two ingredients completely, producing a fluffy, cloud-like texture. After some trial and error, I chose to measure by weight (not volume) and settled on the following ratio: 2 parts bread, 3 parts eggs, 4 parts dairy, 2 parts complements and 1 part of cheese. Keep in mind that a large egg typically weighs 2 ounces.
In order for the bread to absorb as much pastry cream as possible, it must be dried. Oven-drying bread extracts moisture while leaving the crumb structure intact, making oven-dried bread a better option than stale bread.the spread actually restructures the starch molecules, which can lead to unpleasantly rubbery bread. Luckily, it’s simple and it doesn’t take long to dry bread in a low temperature oven.
I let the bread and custard soak in a large bowl for 30 minutes, stirring periodically to make sure the bread is well hydrated, before building up the layers. I’ve found that combining the two directly in a baking dish allows the custard to build up on the bottom, preventing some pieces of bread from getting completely submerged, resulting in an uneven texture in the final layers.
When cooking a stratum, remember that not all cookware is created equal and many brands are not suitable for grilling – before proceeding, be sure to check that your cookware can withstand the heat of a grill! I like Emile Henry’s baking dishes, which are both oven and grill safe. If you are using a dish that is not safe for broilers, like these. made by Pyrex, skip the broiling portion of the recipe (see note).
Strata is easily customizable, so feel free to try your favorite add-ons or swap out different cheeses. Remember that very moist ingredients, such as mushrooms, spinach or diced tomatoes, should be cooked or drained before assembly. Be creative and remember that beyond breakfast, strata also make a wonderful lunch and dinner!