Overnight Onion, Spinach and Cheese Strata

It’s the start of the weekend! Hooray!If you’ve got a brunch coming up, have I got the dish for you! And if you don’t, you might want to think about scheduling one, because this oniony, cheesy, spinachy, breakfast casserole is super special and not to be put on the I’ll-get-to-it-one-of-these-days shelf! Seriously, you’ve got to try this asap!

And whoops, I almost forgot to rave about the best part—you make the entire thing the day before and just pop it into the oven in the morning before your guests arrive. How’s that for stress-free brunching?


What really sets this apart is the generous amount of caramelized onions, adding sweetness and flavor to every bite. So, so worth the time for them to cook! And of course, we can’t ignore the cheese in two places: mixed with the bread and egg mixture and sprinkled on top so that you have gooey cheesiness throughout and that golden crusty top. And you can use practically any kind of cheese you like (my, I’m into my italics today!). I’ve made this with cheddar one time and another with swiss and both received raves from my brunchers (although one of them was a brunch for dinner experience, but that’s another story). Also, the spinach is just present enough to alleviate some of the guilt you might feel at gobbling down all the carbs and cheese (there go those italics again!)

So the next time you host a brunch (and I’m suggesting again that you make it soon, don’t make me nag) do yourself a favor and whip up this wonderful strata in advance, and sleep soundly, knowing that all you have to do is roll out of bed and turn on your oven. Oh, and remind me what time I should be there!! Have a great weekend everyone!


Overnight Onion, Spinach and Cheese Strata

Makes enough for at least 10, more if it is not the only thing you’re serving

Prep Time:  45 minutes  (much of this is just to let onions caramelize) plus at least 2-3 hours and up to 24 for casserole to sit; Bake Time:  1 hour and 15 minutes


  • 1 large loaf of French bread, cut into cubes (enough to fill about 7 cups)

  • 2 tablespoons unsalted butter, plus more for greasing the pan

  • 1 tablespoon canola oil

  • 2 large onions, halved and thinly sliced

  • 1 teaspoon kosher salt, plus more to taste

  • ½ teaspoon black pepper, plus more to taste

  • 8 ounces shredded cheese (any kind you like), divided

  • 10 ounce box frozen chopped spinach, thawed and squeezed dry

  • 10 large eggs

  • 3 cups whole milk

  • 1 cup heavy cream

  • 2 teaspoons Dijon mustard

The Recipe

1.  Preheat oven to 325º F. Place the cubes bread on a large rimmed baking sheet and toast, stirring once or twice, until bread is lightly golden brown, about 10 minutes.  Let cool.

2.  Meanwhile, heat the butter and oil in a large skillet over medium heat until very hot. Add the onions, stir well and season with a pinch of salt and pepper. Cook for about ½ an hour, stirring now and then, until onions are golden brown and caramelized. Set aside to cool a bit.

3.  Butter a 9x13-inch glass baking dish and add the toasted bread cubes. Sprinkle them with ¾ of the shredded cheese, the spinach and the onions. In a large bowl whisk together the eggs, milk, cream, mustard, teaspoon of salt and ½ teaspoon of pepper and pour over the casserole. Push down a bit on everything so that the bread is submerged in the liquid. Cover the dish with aluminum foil and place in the fridge for at least a few hours and up to 24. I always make this the night before and let it sit overnight. 

4.  If you’ve let this sit in the fridge overnight, try to take it out at least 30 minutes before you want to cook it so it comes to room temperature. Preheat oven to 350º F. Cook uncovered and bake for about 1 hour, until the casserole is puffy and golden. Remove from the oven and sprinkle on the remaining cheese across the top. Return to the oven and let cook for another 10-15 minutes so that cheese gets all melted and gooey. Remove from the oven and serve spooning onto plates.


Note:  Recipe adapted from Brunch @Bobby’s by Bobby Flay. I toyed with ingredients and proportions. Feel free to use more or less of anything you like. 



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