1. Preheat oven to 375°F (190°C) and grease a 9×13-inch casserole dish.

2. Cook pasta in salted boiling water until one minute shy of al dente, drain and set aside.

3. In a skillet over medium heat, melt butter and sauté onion until translucent, about 3–4 minutes.

4. Add garlic and cook until fragrant, about 30 seconds.

5. Stir in cream cheese until smooth, then whisk in heavy cream and half of the parmesan until sauce thickens slightly.

6. Season sauce with salt, pepper, and lemon juice, then fold in spinach and artichokes until spinach wilts.

7. Combine pasta, chicken, and sauce, transfer to the baking dish, top with mozzarella, remaining parmesan, and optional bread crumbs, then bake for 20–25 minutes until bubbling and golden. Let rest 5 minutes before serving.