Save This Recipe
We'll email this post to you, so you can come back to it later!
The one side dish I didn’t expect to love this much, but now I can’t live without.
I’ll be real with you: I wasn’t planning on impressing anyone when I made this the first time.
It was the day before Thanksgiving, I was already knee-deep in pie crusts and to-do lists, and I had two bags of frozen spinach in the freezer that had been sitting there since… well, let’s just say they’d been there a while. I was tired, the dog was barking at nothing, and my kitchen timer had just broken. But I needed a green veggie dish. So I started messing around — a little butter here, some cheese there, tossed in a handful of crispy onions because, well, they were open. And something magical happened.
This Crispy Onion Spinach Casserole came out of the oven bubbling and golden, and it smelled like a hug. I didn’t expect much from it. But then my family practically fought over the last scoop, and my sister-in-law texted me later asking if I could “make that spinach thing again next time.” You know what? I absolutely could. And I have — a dozen times since.
So what makes it special?
Let me break it down. This casserole is:
-
Creamy, cheesy, and just a little bit fancy without trying too hard
-
Packed with flavor — not that sad, bland spinach we all grew up pretending to like
-
Topped with crispy onions and buttery panko because life’s too short for soft casseroles
-
Easy to throw together (like, tired-on-a-weeknight easy)
It’s comfort food with some greens in it — so your body and your tastebuds both feel good.
Here’s what you’ll need (and a few things you can fudge)
Listen, I’m not here to judge your grocery haul. This is flexible. Use what you’ve got. We’re cooking, not running a restaurant.
The basics:
-
3 Tbsp butter – To get things going. Salted or unsalted is fine.
-
3 cloves garlic, minced – Fresh is best, but jarred works in a pinch. Been there.
-
3 Tbsp all-purpose flour – Thickens up the sauce.
-
1½ cups whole milk – 2% is okay too. Don’t use skim. Please.
-
A few pantry seasonings – Onion powder, garlic powder, pinch of cayenne (not spicy, just nice), parsley, salt, pepper.
-
2 (10 oz) packages frozen spinach – Thawed and really well drained. Like… squeeze it like it owes you money.
-
4 oz cream cheese – This is what makes it dreamy.
-
1½ cups sharp cheddar, shredded – The sharper, the better, in my opinion.
-
½ cup parmesan – Adds that salty “oomph.”
-
1½ cups crispy fried onions – Half go inside, half on top. Trust the process.
-
½ cup panko breadcrumbs – For crunch. Crushed crackers or chips work too if you’re out.
Let’s cook. I promise it’s easy.
Step 1: The creamy stuff
Melt the butter in a big ol’ skillet. Toss in the garlic and let it do its thing for a minute or two — just until your kitchen smells like “Ohhh what’s that?”
Whisk in the flour and let it cook a bit, just until golden and kind of toasty. This part matters — it gives your sauce depth and keeps it from tasting floury.
Now slowly pour in the milk, whisking as you go. Let it simmer until it thickens a bit. You want it creamy, not gloopy.
Add your seasonings here. Don’t skip the cayenne — it’s not about heat, it’s about flavor.
Step 2: Cheese party
Turn the heat to low and stir in the cream cheese, cheddar, and parm. Watch it melt into the sauce like it was meant to be there.
Try not to eat a spoonful at this point. Or do. I won’t tell.
Step 3: The greens
Add in that spinach. Make sure it’s really well-drained or things get watery fast. Stir it into that cheesy mix until everything’s combined. Then fold in about 1 cup of your crispy onions. Yep, right into the casserole. They give it the best texture.
Step 4: Bake it
Grease an 8×8 dish. Scoop in your spinach-cheese mixture. Smooth it out a little, then sprinkle the top with the panko and the rest of the crispy onions.
Pop it in a 350°F oven for about 30–35 minutes, or until it’s golden and bubbling and smells like comfort.
Let it sit for 5 minutes before digging in. Mostly so you don’t burn your mouth, but also because it sets up a bit better.
Want to mix it up? You’ve got options.
-
Add sautéed mushrooms for a little earthiness.
-
Stir in chopped cooked bacon (I mean… yeah).
-
Swap in Gruyère, Swiss, or pepper jack if you’re feeling sassy.
-
No panko? Use crushed Ritz crackers. I’ve done it. Delicious.
Leftovers (if you even have them)
This casserole keeps beautifully.
-
Fridge: Up to 4 days, covered. Reheat in the oven or microwave.
-
Freezer: Freeze before baking (leave off the topping), then thaw and bake when ready. Add the crispy stuff just before baking so it stays, well, crispy.
Pro tip: Double the batch and freeze one. Your future self will be so grateful.
Alright, that’s it.
I know casseroles aren’t always glamorous. But this one? It’s something special. It’s the thing you make when you want comfort without fuss. When you want to feed people you love something warm and real.
And if you make it, I hope it brings you the same surprise joy it brought me that day — apron half-on, music playing, chaos in the background, and somehow… everything coming together just right.
Let me know if you try it, okay? I’d love to hear what you think — or how you made it your own. We’re all just figuring it out in the kitchen together anyway.
Big hugs from my stove to yours,
Crispy Onion Spinach Casserole
Ingredients
- 3 tablespoons butter
- 3 cloves garlic, minced
- 3 tablespoons all-purpose flour
- 1 1/2 cups whole milk
- 1/2 teaspoon onion powder
- 1/4 teaspoon garlic powder
- 1 pinch cayenne pepper
- 1 teaspoon dried parsley
- 1/2 teaspoon salt
- 1/4 teaspoon pepper
- 1 1/2 cups crispy onions, divided
- 1/2 cup panko bread crumbs, divided
- 2 10 oz packages frozen spinach, thawed and drained
- 4 oz cream cheese, room temperature
- 1 1/2 cups shredded sharp cheddar cheese
- 1/2 cup parmesan cheese
Instructions
- Melt butter in a skillet over medium heat. Add minced garlic and cook for 2 minutes.
- Whisk in flour and cook for 1-2 minutes until golden in color.
- Slowly whisk in milk and bring to a low boil for 3-4 minutes until thickened.
- Stir in onion powder, garlic powder, cayenne, parsley, salt, and pepper.
- Preheat oven to 350°F. Stir spinach, cream cheese, cheddar cheese, and parmesan into the roux. Reduce heat and stir until melted and combined.
- Remove from heat and stir in 1 cup of the crispy onions.
- Transfer mixture to a greased 8x8-inch baking dish. Top with panko breadcrumbs and remaining crispy onions.
- Bake for 30-35 minutes or until golden brown and bubbling. Serve warm.
Notes