Roast the squash: Preheat your oven to 400°F (200°C). Halve the spaghetti squash lengthwise and scoop out the seeds. Rub the cut sides with olive oil, season with salt and pepper, and place cut-side down on a parchment-lined baking sheet. Roast for 30–40 minutes, until the strands pull apart easily with a fork but still have a slight bite.

Prep the chicken: While the squash roasts, pat chicken dry and season both sides with salt, pepper, and half the Italian seasoning.

Sear the chicken: Heat a large skillet over medium-high heat with 1–2 tablespoons olive oil (or oil from the sun-dried tomatoes). Sear chicken 4–5 minutes per side until browned and cooked through (165°F/74°C). Transfer to a plate and tent with foil. Let it rest, then slice or cube.

Sauté aromatics: Lower heat to medium. Add butter if using. Stir in minced garlic and chopped sun-dried tomatoes. Cook 1 minute until fragrant, scraping up any browned bits.

Make the sauce: Pour in chicken broth and simmer 2 minutes. Add heavy cream, remaining Italian seasoning, and a pinch of red pepper flakes if you like heat. Simmer gently 3–4 minutes to thicken slightly, stirring often.

Add greens and cheese: Stir in spinach and let it wilt. Sprinkle in Parmesan a little at a time, stirring until smooth. Taste and adjust salt and pepper. The sauce should be creamy and well seasoned.

Combine with chicken: Add the sliced chicken back to the skillet and coat with the sauce. Keep warm on low.

Shred the squash: When the squash is cool enough to handle, use a fork to pull the strands into “spaghetti.” You can serve it in the squash boats or transfer to a wide bowl.

Assemble: Spoon the Tuscan chicken and sauce over the squash strands. Toss gently to coat, or plate the squash and top with chicken. Garnish with extra Parmesan and fresh basil if you’d like.

Serve: Plate immediately while hot. Add a squeeze of lemon if you want a brighter finish.