Ingredients

1 medium spaghetti squash (about 2 1/2 lb.)

1 tbsp. neutral oil

1 3/4 tsp. kosher salt, divided

6 oz. broccoli, cut into 1" florets (about 1 1/4 cups)

1 tbsp. plus 1/4 cup water, divided

3 tbsp. unsalted butter

1/2 yellow onion, finely chopped

3 garlic cloves, minced

1 tbsp. all-purpose flour

1/2 cup whole milk

4 oz. cheddar, shredded, divided (about 1 cup)

Instructions

Step 1: Arrange a rack in the center of the oven and preheat to 400°. Cut the spaghetti squash in half lengthwise and scrape out the seeds. Rub the inside of each half with the oil and season with 1 teaspoon of salt. Place the squash halves cut side down on a baking sheet.

Step 2: Roast the squash until tender and browned, about 35 to 45 minutes. Remove from oven and let cool slightly.

Step 3: Meanwhile, place the broccoli florets in a medium heatproof bowl and sprinkle with 1/4 teaspoon salt. Pour 1 tablespoon water into the bottom of the bowl. Cover and microwave for 1 minute, then stir. Continue microwaving in 30-second increments until the broccoli is bright green and fork-tender, about 30 seconds to 1 minute more. Uncover and set aside to cool slightly.

Step 4: In a large skillet over medium heat, melt the butter. Add the chopped onion and season with 1/2 teaspoon salt. Cook, stirring occasionally, until the onion is tender and sweet, about 7 to 8 minutes. Add the garlic and cook, stirring, until fragrant, about 1 more minute. Stir in the flour and cook until a bubbling paste forms on the bottom of the skillet, about 1 minute.

Step 5: Slowly whisk in the milk and the remaining 1/4 cup water. Bring the mixture to a simmer over medium-high heat and cook, stirring occasionally, until thickened, about 1 to 2 minutes. Remove from heat and fold in 3 ounces of shredded cheddar until the sauce is smooth. Taste and season with salt if needed.

Step 6: Using two forks, shred the roasted spaghetti squash strands from the shells. Measure out 3 cups of strands and transfer them to the skillet with the sauce. Reserve any remaining squash for another use. Add the cooked broccoli to the skillet and toss everything to coat evenly in the cheese sauce.

Step 7: Return the cheesy spaghetti squash and broccoli mixture to the empty squash shells. Sprinkle the remaining 1 ounce of cheddar evenly over the top.

Step 8: Heat the broiler. Place the squash halves under the broiler and watch closely. Broil until the cheese is melted and blistered in spots, about 1 to 2 minutes. Serve warm.

Tips & Variations

For extra flavor, sprinkle some smoked paprika or cayenne pepper into the cheese sauce before adding the cheddar.

Feel free to swap the broccoli for other vegetables like spinach, cauliflower, or peas.

Use a sharp cheddar for a more pronounced cheesy taste or mix cheddar with mozzarella for a creamier texture.

To save time, you can microwave the halved spaghetti squash cut side down for 10-12 minutes instead of roasting, though roasting develops more flavor.

FAQs

Can I prepare this dish ahead of time?

Yes, you can roast the spaghetti squash and cook the broccoli and sauce ahead of time. Assemble and broil just before serving to keep the cheese topping fresh and bubbly.

What if I don’t have a microwave to steam the broccoli?

You can steam the broccoli on the stovetop by placing it in a steamer basket over boiling water for 3 to 5 minutes, until bright green and tender. Alternatively, blanch in boiling water for 2 minutes and then drain.