This salmon spaghetti squash bake is a tasty seafood casserole (or gratin) made with squash, milk, Parmesan cheese, and salmon. Prepare it ahead of time for a quick dinner!
How do you feel about spaghetti squash?
Do you love it?
We’ve been eating lots of spaghetti squash this month, and I’ve been enjoying every bite!
If you’ve been following along with my Instagram stories, you’ve probably seen some spaghetti squash.
But guys, spaghetti squash can be a little tricky to cook with. Much like zucchini, this squash holds onto a lot of moisture and has an very mild flavor.
As we were devouring spaghetti squash marinara one night, I had an idea. Since spaghetti squash acts like zucchini, why not treat it like zucchini?
I decided to try adapting this summery zucchini gratin into a winter squash recipe, and (after a few tries) we fell in love with this fabulous fall meal.
Happily, we also had lots of fish on hand, and this quickly turned into a salmon spaghetti squash bake.
How Do I Cook Spaghetti Squash?
For this recipe, you only need half of a spaghetti squash, and you can cook it however you prefer.
I recommend cooking the entire squash, and then storing the remaining squash in the fridge to use later.
I generally roast spaghetti squash, because cooking it in the oven helps the squash develop delicious sweet flavors.
If you prefer, you can also cook your spaghetti squash in the Instant Pot. Either method works perfectly here.
How To Remove Salmon Skin
I really don’t enjoy cutting the skin off salmon, but for this recipe it’s a good idea.
The skin is edible, but it won’t be crisp after cooking. I recommend removing the skin before cooking, otherwise it will end up in the casserole.
To remove the skin, place the salmon skin-side up on a cutting board. Use a sharp knife (such as a fillet knife) and cut parallel to the fish’s natural grain.
If you have a hard time removing the fish skin cleanly, it’s okay. The spaghetti squash will hide any imperfections.
How to Make a Salmon Spaghetti Squash Bake
Start by cooking the squash in a large, oven-safe pan. I used this Lodge 12″ carbon steel skillet.
Season the squash with salt, garlic powder, and red chili flakes. As it cooks, some of the water in the squash will evaporate.
Next, add a little flour. Gluten-free all purpose flour (such as Cup 4 Cup) will work perfectly.
Stir the squash until the flour is absorbed.
Slowly pour in a cup of milk.
Bring the liquid to a simmer, and cook for a few minutes until the milk begins to thicken.
Stir in some Parmesan.
Next, make an indention in the squash.
A salmon-sized indention.
Place the salmon into the pan.
Sprinkle more Parmesan over the entire dish and drizzle a little olive oil on top.
Bake the salmon until the fish is opaque and tender.
Finally, switch on the oven’s broiler until the cheese begins to turn golden.
Serve this salmon spaghetti squash bake right away, along with a piece of toasted bread and a crisp glass of dry hard cider.
Salmon Spaghetti Squash Bake
- 1 ½ pounds spaghetti squash (½ of a standard sized 3lb squash)
- 8 ounces salmon (2 fillets)
- 3 tablespoons olive oil (divided), plus more for cooking the spaghetti squash
- 2 teaspoons garlic powder (or 2 garlic cloves, minced)
- ½ teaspoon sea salt, plus about two pinches of salt (for squash + salmon)
- ¼ teaspoons red pepper flakes
- 2 tablespoons flour Use AP gluten-free flour if needed
- 1 cup milk
- ⅔ cup Parmesan, freshly grated (divided) Or substitute Swiss, Jarlsberg, or Smoked Gouda
Cook the Spaghetti Squash:
- Cook squash according to your desired preference. You're only using half the squash. The remaining squash can be stored in the fridge and used within 3-4 days.Oven Directions: Cut squash in half and remove the seeds. Drizzle with oil and a pinch of salt (if desired). Roast cut-side down on a baking sheet at 400°F for about 40 minutes, or until the squash is easily pierced with a fork.Pressure Cooker: See Instant Pot directions.Allow squash to cool slightly. Use a fork to scrape the spaghetti squash out of the peel (from one half only).
Prepare the Salmon:
- If your fish has skin, place the fish skin-side up on a cutting board. Use a sharp knife (a fillet knife is best) to cut the skin off the fish, keeping the knife blade parallel to natural grain of the fish.Tip: If you struggle with removing the skin, it's okay. Any mistakes will be hidden by the squash, and any extra pieces stuck to the skin can be removed and placed under the salmon fillets in the pan.Season the salmon lightly with sea salt. Set the fish in the fridge and discard the skin.
Make the Casserole:
- Preheat oven to 370°F and move an oven rack to the top position (near the broiler).Heat 2 TB olive oil over medium heat in a large, oven-safe pan (like cast iron or carbon steel).Add the spaghetti squash, garlic,, salt and red pepper flakes. Cook about 3 minutes to remove some of the moisture from the squash.
- Add the flour to the squash mixture and stir. Cook about 2 minutes until the flour is incorporated. Stir well and make sure there are no lumps of uncooked flour before proceeding.
- Slowly pour the milk into the pan, stirring as you pour. Continue cooking until the liquid begins to simmer.Simmer for about 2 minutes (or until the milk begins to thicken), and then stir in ½ cup of the cheese. Make Ahead Tip: If desired, you can stop at this point and finish cooking later. Make up to one day ahead, and then reheat to a simmer before proceeding to the next step.
- Take the salmon out of the fridge.Use a spoon to make a large indention in center of the squash mixture (large enough for the salmon).Set the salmon into the squash. Sprinkle the remaining cheese across the top of the squash and salmon, and drizzle with the remaining 1 TB oil.
- Carefully move the pan into the oven onto the top rack. Bake 15 minutes, until the salmon is opaque, tender and the cheese has melted. Tip: If your salmon is very thick (more than about an inch and a half thick), it may need a longer cook time. Watch for the salmon to turn opaque.
- Position the pan so that it's directly under the broiler. Turn on the broiler and cook for 2 more minutes, until the cheese is golden. (If your oven does not have a broiler, simply cook 2 more minutes.)Serve immediately.