1. Preheat and prep

Preheat your oven to 425 °F (≈ 220 °C). Line a baking dish (or two) or a rimmed sheet.

2. Prepare the cheese mixture

In a medium bowl, combine the milk (or cream), chopped & squeezed spinach, fresh sage, and thyme leaves. Add fontina and mozzarella (or gouda) and stir to combine. Season with red pepper flakes (if using), kosher salt, and black pepper.

3. Stuff the squash

Place your halved spaghetti squash cut side up in the baking dish. Season the cut surfaces with salt and pepper.
Sprinkle half of the provolone cheese into the bottom cavities of each squash half.
Then pour/divide your milk‑cheese‑spinach mixture evenly into each squash cavity. Top each with the remaining provolone and then sprinkle the parmesan over the top. Cover the entire baking dish (or squash) with foil.

4. Roast the garlic

While the squash is baking, take the garlic head. Slice off the top portion (about ¼–½ inch) to expose the cloves. Place the garlic on a piece of foil, drizzle with olive oil, and wrap it up tightly.

5. Bake squash & garlic

Bake both the covered squash and wrapped garlic for 30 minutes. Then remove the foil from both and continue baking 15–20 more minutes, or until the squash is tender (you can pierce with a fork) and the cheese is melted and golden.

6. Mash roasted garlic & finish

Allow the garlic to cool a bit. Squeeze the softened roasted garlic cloves into a small bowl. Add the butter and 1 tablespoon fresh sage (finely chopped). Mash well with a fork to form a garlic‑butter paste.

Spread that garlic butter over the squash halves. Then, using a fork, scrape the squash flesh into strands (spaghetti style), mixing it with the melted cheese inside. Let the squash absorb the sauce and cheeses fully. Serve warm and enjoy!