2medium spaghetti squash, halved lengthwise and seeds removed
Olive oil, for drizzling
2cupsmilk (can use skim, 1%, 2% or whole)
8ouncessharp cheddar cheese, shredded
1cuppanko bread crumbs
Preheat oven to 375 degrees F. Line a sheet pan with parchment paper or foil.
Drizzle squash with olive oil and season with salt and pepper. Place cut side-down on prepared sheet pan and bake until fork tender, about 45-60 minutes.
Let spaghetti squash sit a few minutes until cool enough to handle, then shred flesh with a fork.
In a large skillet, melt 2 tablespoons of the butter. Add flour and stir with a whisk until it makes a thick paste.
Slowly pour the milk into the pan while whisking constantly. Bring to a boil, then cook for a few minutes until thickened, stirring frequently.
Add the cheddar cheese, mustard powder, salt and pepper and stir until smooth.
Add spaghetti squash and toss until combined. Divide evenly into the 4 squash skins.
Melt the remaining 1 tablespoon of butter. Add the panko bread crumbs and stir until all the bread crumbs are moistened. Sprinkle on top of the spaghetti squash.
Bake until filling is bubbling and topping is browned, about 20 minutes. Serve immediately.
To cook spaghetti squash in instant pot: Place trivet inside your instant pot, then fill with 1 cup water and add the spaghetti squash. Set high pressure to 6 minutes and use a quick release.
To cook spaghetti squash in the microwave: Place spaghetti squash cut side-down into a microwave-safe dish that will fit your microwave and add 1/2 cup water. Microwave on high for about 15 minutes until fork tender (time will vary based on side of spaghetti squash).