Preheat and prep the squash. Heat the oven to 400°F (200°C). Carefully halve the spaghetti squash lengthwise and scoop out the seeds. Rub cut sides with 1 tablespoon olive oil and a pinch of salt and pepper. Place cut-side down on a parchment-lined sheet pan.

Roast until tender. Bake 35–45 minutes, depending on squash size. It’s ready when the skin gives slightly and the strands pull apart easily with a fork. Remove from the oven and cool just enough to handle.

Season the chicken. While the squash roasts, pat chicken dry. Toss with 1 tablespoon olive oil, 1 teaspoon salt, 1/2 teaspoon pepper, garlic powder, onion powder, and Italian seasoning.

Cook the chicken. Heat a large skillet over medium-high. Sear chicken 4–6 minutes per side until browned and cooked through (165°F/74°C internal). Transfer to a plate and rest 5 minutes, then slice or cube.

Make the Alfredo sauce. Lower the skillet heat to medium. Add butter. When melted, add minced garlic and cook 30–60 seconds until fragrant. Pour in heavy cream and chicken broth. Bring to a gentle simmer.

Finish the sauce. Whisk in Parmesan until melted and smooth. Stir in cream cheese if using. Add a pinch of nutmeg. Simmer 2–3 minutes to thicken slightly. Taste and adjust salt and pepper.

Shred the squash. Use a fork to pull the roasted squash into strands. Transfer to a large bowl and lightly season with salt if needed. If strands seem wet, let them steam off for a minute to reduce moisture.

Combine. Add sliced chicken to the Alfredo sauce and toss to coat. Fold in the squash strands until everything is creamy and well-distributed. If it feels too thick, splash in a bit more broth or cream to loosen.

Portion for meal prep. Divide into 4–5 containers. Top with extra Parmesan, chopped parsley, and a pinch of red pepper flakes if you like heat.

Cool and store. Let containers cool uncovered for 10–15 minutes before sealing to avoid condensation.