1. Roast garlic: Trim the top off the garlic head, drizzle with a little olive oil, wrap in foil, and roast for 20 minutes until soft. Cool and mash into a paste.

2. Prepare meat sauce: Heat 1 Tbsp olive oil in a large pot over high heat. Brown the sausage for 5-8 minutes, add onion and cook for 2 minutes. Reduce heat, stir in crushed tomatoes, 1 cup water, bay leaf, oregano, salt, and pepper. Simmer for 15 minutes until thickened, then mix in the roasted garlic paste and adjust seasoning.

3. Prep squash: Poke each spaghetti squash with a fork and microwave for 3 minutes (or halve, seed, and pre-roast cut-side down for 15 minutes at 425°F). Cool slightly, cut lengthwise, and scoop out seeds.

4. Cheese mixture: In a bowl, combine milk, ricotta, nutmeg, basil, salt, and pepper. Fold in 1 cup Fontina and 1/2 cup provolone.

5. Assemble: Place squash halves in a baking dish, season cut sides with salt and pepper, and sprinkle the remaining Fontina inside each half. Spoon the meat sauce evenly over the squash, then dollop the ricotta mixture on top. Finish with the remaining provolone and cover loosely with foil.

6. Bake: Bake for 20 minutes covered, then remove foil and bake an additional 15-20 minutes until the squash is tender and the cheese is golden. Let rest for 5 minutes, then scrape the flesh into strands, mixing with the sauce and cheese. Garnish with thyme or fried sage if desired.