HOW TO MAKE IT :
- Grease a 9×13 inch (or similar size) casserole dish or spray with nonstick spray.
- Arrange bread in a single layer in the pan, then set pan aside.
- Cook bacon according to package stovetop directions in a large skillet. Drain all but about 1 Tablespoon grease. (Or drain it all and add 1 Tablespoon olive oil for the next step.) Cool bacon until ready to handle, then chop into bite-size pieces. Sprinkle over bread.
- Add onion to greased skillet. Cook on medium heat until soft, about 4 minutes. Add garlic and spinach and while stirring occasionally, cook until spinach has wilted, about 2-3 minutes. Remove from heat. Spoon evenly over the bread/bacon, then sprinkle all of the cheese on top.
- Whisk eggs, milk, salt, ground mustard, and pepper together in a large bowl. Pour evenly over cheese. Cover tightly and refrigerate for 1 hour or overnight (up to 12-16 hours).
- Remove casserole from the refrigerator and allow to sit out at room temperature for 15 minutes.
- Preheat the oven to 375°F (191°C).
- Bake casserole, uncovered, for 20 minutes. Loosely cover with aluminum foil and bake for 30-35 minutes. The casserole is done when browned on the sides and puffy in the center– usually takes 50-55 minutes total.
- Remove from the oven, sprinkle optional garnish(es) on top if using, and allow to cool for 5 minutes before serving.
- Cover leftovers tightly and store in the refrigerator for up to 5 days. Reheat in the microwave.
Notes
- Freezing Instructions: Prepare through step 5, then cover the casserole with plastic wrap, then a layer of aluminum foil. These 2 layers are ideal for protecting this egg heavy dish in the freezer. Freeze for up to 3 months. Thaw overnight in the refrigerator, then bring to room temperature, and continue with step 7.
- Bread: Use homemade crispy, crusty bread such as artisan bread or purchase a loaf or baguette from your grocery store’s bakery. If you can get your hands on a crusty loaf of sourdough bread, definitely use it here. It’s wonderful in this strata. For best taste and texture, cut the loaf into large bite-size chunks, then let the chunks sit out for several hours or overnight (uncovered) to dry out. They soak up more liquid this way.
- Spinach: You can use an 8-10 ounce package of frozen spinach instead if desired. Thaw, then blot out excess moisture. Sauté in step 4 just as you do the fresh spinach. You could also use fresh kale or arugula instead.
- Bacon/Cheese/Flavor Substitutions: See “Some Key Ingredients & Substitution Options” above.
