Caramelized Onion and Spinach Stuffing

Let’s continue the Thanksgiving recipe train, shall we?! With this caramelized onion and spinach stuffing!

Or otherwise known as the stuffing of my dreams.

A white baking dish filled with Caramelized Onion and Spinach Stuffing.

And then, then there’s my husband.

Who doesn’t like this version as much as the classic stuffing that I typically make for turkey day. Why you ask? Because … wait for it … there’s no celery involved. Who is he????

And please, for the love of goodness, don’t go and get any crazy ideas from him and try to add celery to today’s recipe. Just no. No. No. No.

There’s a time and place for celery and today’s dish sure ain’t one of them! Because do we want to mess with the wonder that is caramelized onion? I don’t think so!

Now, I am a firm believer that no Thanksgiving menu is complete without a killer stuffing. And today’s recipe most certainly fits the bill. We’re talking chunks of sourdough, oh-so-flavorful caramelized onions and wilted spinach tossed together and baked to perfection. You know what I’m talking about – crisp on the top but still perfectly soft underneath.

And yes, I am totally counting down the days until I get to eat this again on Thanksgiving…

Overhead view of a tray of Caramelized Onion and Spinach Stuffing with a silver spoon in the dish.

Tips & Tricks For This Caramelized Onion and Spinach Stuffing

  1. Because we are caramelizing the onions, the cook time for this recipe is on the longer side. So here’s my suggestion. Caramelize the onions / wilt down the spinach (this is all done in the same skillet!) in advance. Let cool to room temp and then store in an airtight container in the fridge. On turkey day, all you’ll need to do is toss everything together in a big bowl and then bake off in the oven. Keeping it nice and simple for the day of!
  2. I’d also suggest cubing up the bread a day ahead of time. It helps the bread get even more stale (which we want) AND saves time on Thanksgiving. Win win!
  3. To make this recipe dairy free, use olive oil in place of the butter.
  4. I think the stuffing is pretty darn awesome as written, but if you love a lot of “stuff” in your stuffing, you may want to add more onions (I’d suggest maybe one more). But it really just depends on your preference!
  5. Salt. The first time you make this I’d recommend using the amount listed below. If you want to add more, you can always sprinkle some over the top at the very end.

Turkey day carbs. The best. Just the absolute best! Am I right, or am I right??

A white baking dish with Caramelized Onion and Spinach Stuffing with a serving spoon in the pan.

Additional Thanksgiving Recipes You Might Enjoy!

Did you make this recipe? Rate and review it down below! I’d love to hear from you.

Caramelized Onion and Spinach Stuffing

Caramelized Onion and Spinach Stuffing

Yield: about 6 to 8 servings
Prep Time: 15 minutes
Cook Time: 1 hour 30 minutes
Total Time: 1 hour 45 minutes

Cozy caramelized onion and spinach stuffing! With sourdough bread and oh-so-flavorful caramelized onions. A fun twist on classic stuffing for the holidays!


For the onions:

  • 3 tablespoons unsalted butter, cut into chunks
  • 2 large onions, thinly sliced
  • ¼ teaspoon salt
  • ¼ cup low-sodium vegetable broth
  • 1 (5 ounce) bag fresh baby spinach leaves

For the stuffing:

  • 1 (1 pound) loaf stale sourdough, cut into ½ to ¾ inch cubes
  • 1 ¼ cups low-sodium vegetable broth
  • 1 large egg
  • ½ teaspoon salt
  • ¼ teaspoon pepper


For the onions:

  1. Set a large skillet over medium heat. Add in the butter. When melted, add in the onions and salt and toss to combine. Cook for about 30 to 45 minutes, stirring occasionally, until the onions are a caramel brown. {Turn down the heat to medium low or low if they start cooking too fast or are burning (you can also add a little oil or additional butter to the skillet if needed). Toward the end of the cooking, you’ll want to stir more frequently.}
  2. Once nicely caramelized, add the broth to the skillet and use a wooden spoon to scrape up any bits from the pan. Add in the spinach and cook for about 2 to 3 minutes, stirring frequently, until the liquid has evaporated and the spinach is wilted. Remove from the heat.

For the stuffing:

  1. Preheat the oven to 375ºF. Mist a 9x13 inch baking dish with nonstick or olive oil spray. Set aside.
  2. Add the bread cubes to a large bowl, along with the onion mixture. Toss to combine. In a small bowl or liquid measuring cup, whisk together the broth, egg, salt and pepper. Pour into the bowl with the bread and toss until everything is evenly coated.
  3. Transfer the mixture to the prepared baking dish and cover with aluminum foil. Bake for 30 minutes. Remove the aluminum foil and bake for about 20 additional minutes, until the top layer is golden brown and crisp.
Nutrition Information:
Yield: 8 Serving Size: 1
Amount Per Serving: Calories: 229 Total Fat: 6g Saturated Fat: 3g Trans Fat: 0g Unsaturated Fat: 3g Cholesterol: 35mg Sodium: 606mg Carbohydrates: 35g Fiber: 2g Sugar: 5g Protein: 8g
Nutrition data shown is an estimate provided by an online calculator and is for informational purposes only. It should not be considered a substitute for a medical professional’s advice.