Prep the oven and pan: Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with olive oil or cooking spray.

Cook the cauliflower: Steam or microwave the florets until just tender, about 5–7 minutes. Drain well and pat dry with paper towels to remove excess moisture.

Cook the chicken if needed: If you don’t have pre-cooked chicken, season raw chicken with salt and pepper, sear in a skillet with a little oil for 4–5 minutes per side, then chop or shred. Rotisserie chicken also works great.

Make the Alfredo sauce: In a large skillet over medium heat, melt the butter. Add garlic and cook until fragrant, about 30 seconds.

Build the cream base: Stir in the cream cheese and heavy cream, whisking until smooth. Add chicken broth to loosen the sauce and simmer gently for 2–3 minutes.

Season and add cheeses: Stir in Parmesan, 1 cup mozzarella, Italian seasoning, salt, and pepper. Simmer until the sauce thickens slightly, 2–3 minutes. Adjust seasoning to taste.

Combine: In a large bowl, mix the cooked cauliflower and chicken. If using spinach or mushrooms, sauté them quickly in a little oil and add them to the bowl. Pour the Alfredo sauce over everything and toss to coat.

Assemble the bake: Spread the mixture in the prepared baking dish. Top with the remaining 1/2 cup mozzarella and a little extra Parmesan, if you like.

Bake: Bake for 18–22 minutes, until bubbly around the edges.

Broil for color (optional): Switch to broil for 1–2 minutes to brown the top. Watch closely.

Rest and serve: Let it rest for 5–10 minutes. Garnish with parsley and a pinch of red pepper flakes, if desired.