Strata with Caramelized Onions, Mushrooms and Smoked Mozzarella – Recipe

Strata with Caramelized Onions, Mushrooms and Smoked Mozzarella
Strata with Caramelized Onions, Mushrooms and Smoked Mozzarella

Strata: a baked egg dish filled with cubes of bread and whatever awesomeness you can muster. I.e. it has all of the appeal of a quiche, but without the slight hassle of pie crust. Also, the starch from the bread tends to stabilize the custard, so you have a somewhat wider safety margin between unset eggs and overcooked, rubbery eggs.

Today's version features a big pile of caramelized onions and sauteed mushrooms, flavored with fresh tarragon, garlic, black pepper, and nutmeg. The caramelized onions take a while to produce, but you can make this whole dish the night before a brunch, refrigerate it, and then just bake it off in the morning while you and your guests drink coffee and pray that whatever mess the kids are making in the other room isn't irreparable. Hey, it seems awfully quiet in there! 

 Strata with Caramelized Onions, Mushrooms and Smoked Mozzarella
Vegetarian
Serves 6

  • 4 medium white onions, sliced 1/8" thick
  • Butter
  • Kosher salt 
  • 3/4 pound crimini mushrooms, sliced generous 1/4" thick
  • 2 cloves garlic, thinly sliced
  • 8 eggs, well beaten
  • 2 3/4 cup milk
  • 2 teaspoons Dijon mustard
  • 1/4 teaspoon chili flakes
  • 1 tablespoon minced fresh tarragon (packed)
  • Freshly ground black pepper
  • Freshly grated nutmeg
  • 7 ounces smoked mozzarella, grated or cut into small cubes
  • 4 1/2 cups artisan bread, 1/2" cubes (slightly stale is fine)
  1. Melt 3 tablespoons butter in large skillet over medium-low heat. Add the onions, which will fill it practically to overflowing, and 1/4 teaspoon of Kosher salt. Cook, stirring ocassionally, until they are reduced to gooey brown awesomeness. You'll probably need to lower the heat part way through to avoid burning. The whole process will take about an hour, and when you are done you'll have a generous cup of caramelized onions.
  2. Remove the onions, add another 2 tablespoons of butter, raise the heat to medium-high, add the mushrooms, garlic, and a big pinch of salt and saute until slightly softened and browned, about 5 minutes. Remove from heat.
  3. Preheat oven to 350. Butter a casserole that is about 9" x 11" x 2". (Unless you are making this in advance, in which case don't preheat the oven now, duh; refrigerate the dish after step 5 and allow about 10 minutes extra time when baking from cold.)
  4. In a large bowl, whisk together the eggs, milk, mustard, chili flakes, tarragon, 1 1/2 teaspoons of salt and generous quantities of pepper and nutmeg. Stir in the onions, mushrooms and cheese.
  5. Put the cubed bread in the casserole and pour the egg mixture over it. Toss to distribute well. 
  6. Bake until the custard is set and the top is lightly browned, about 40 minutes. It should feel reasonably firm when touched in the center and there should be no jiggle to it, but don't overbake or the eggs can become grainy.
  7. Allow to cool at least 10 minutes, then serve either hot, warm, or near room temperature. 

20 Replies to “Strata with Caramelized Onions, Mushrooms and Smoked Mozzarella – Recipe”

  1. Oh my goodness, I’m flagging this one for Thanksgiving morning. Love all the flavors – you’re so right about a strata being a bit more forgiving than a quiche (although I count both among my favorites). Wish I had a piece now!

  2. I imagine that should work just fine! This recipe wants some free starch, but I don't think it cares about the gluten at all.

  3. Love this blog — lots of great recipes that I hope to try out some day! I recently started a blog that you and your readers might find interesting: http://withoutbacon.wordpress.com . The premise of the blog is that it’s really hard to find nice restaurants (currently focusing on New York, but with a few other cities sprinkled in from time to time) with good vegetarian options (and by “good”, I mean “not just mixed vegetable pasta”). So it’s like a restaurant review, but focusing on what’s vegetarian, and holding these ‘top chefs’ to their own standards. Check it out and let me know if you have any feedback — much appreciated — and would love if you saw fit to mention on your blog. Thanks!

  4. Very cool. I like what you are doing, as I often have the issue that when I travel I want to know (a) what are the great local restaurants (which I can usually figure out without enough research) and (b) which ones of them have serious vegetarian options (which can be much harder to discern). I especially like the pictures, as that makes it pretty easy for me to decide for myself if a place should be on my radar. Nice work!

  5. I made this last weekend as the main dish for a (challenging) dinner party of vegetarians and committed meat-eaters —
    Everybody loved it; it was completely delicious and very rich tasting. They wanted the recipe, so I gave them your website. I am riffing off it this weekend again for my family. I thank you very much for this great recipe.

    1. I’m glad it was a hit! And indeed, that is a very “riffable” recipe. Let me know what you come up with, and thanks for sharing the site with your friends too, I really appreciate that.

  6. It came out scrumptious-ly (if that is a word).

    This time I used what I had left from the last farmers’ market and some odds and ends from the fridge:

    two big leeks, a few stalks of celery, a few cloves of garlic, sauteed slow and long in olive oil,
    with lots of fresh thyme (+ sea salt and fresh ground pepper)

    sliced baby bellas sauteed in 2.5 Tbs butter (again, + a little sea salt and fresh ground pepper)

    seven medium potatoes, boiled

    A roux, with milk (and a little heavy cream), into which I threw about 6 oz smoked mozzarella (left over from making your recipe), and a big dash of cayenne.

    About 2 cups of chopped kale, uncooked.

    I put everything into a large oval le creuset, and stirred it together. On top I slice an heirloom tomato, and sprinkled some parmesan.

    I covered it and baked it at 350 for, I don’t know, maybe 40 minutes, then I uncovered it and cooked it til everything was bubbly and tinged with brown on top.

    I apologize for the seat of the pants nature of this –

    It was so tasty! Your recipe – which was dazzling – gave me the inspiration to pull my hodge podge of ingredients together into something that was really savory and satisfying.

    Thanks again, Michael.

  7. I’ve been a sweet bread pudding baker since … my first baked recipe at 12yrs.old !!!

    I started making savory ones, flying by the seat of my pants ’cause I’d never seen a recipe for one, when I moved in with a Vegetarian housemate. Her idea of a meal was popcorn and leftover Wasabi sauce; (loves food ~ didn’t cook). We worked together in an up-scale cuisinery restaurant, so didn’t cook meals at home more than once a week. Savory bread pudding became the go-to. There was always one in the fridge … ’cause there’s always some form of bread on the counter, and always bits of veggies and cheese in the fridge.

    I recently made one with Lays Tomato-Basil potato chips (kids weren’t eating them), layered with roasted peppers, mushrooms, shallots and cheeses, dried basil. Poured the custard on top and … voila! Kids thought it was excellent !

    You can also make these with bits of leftover meats, but don’t tell your Vegetarians you go there when they’re not looking!

  8. This recipe sounds as good as the picture of the final result. I love the idea of using smoked mozzarella. You’ve given me a good starting point for coming up with my own outdoor cooked strata. Thanks!

  9. I made two mini versions of this strata for dinner tonight for my husband and me using leftover bread he had made earlier in the week and it was fantastic! I substituted sage from the garden (I didn’t have fresh tarragon), used tarragon olive oil in addition to butter to sauté the mushrooms, and did not have smoked mozzarella but some plain I had made so used smoked sea salt instead of the regular Maldon’s we use. Wow. I will try it again once I have your full ingredients but this was a killer dinner with a small salad. I went a little nuts and made 5 mini ones and now have a bunch for lunch tomorrow. Thank you!!

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