Prep the oven and pan: Heat oven to 400°F (200°C). Lightly oil a large baking dish.

Prepare the zucchini boats: Slice each zucchini in half lengthwise. Use a spoon to scoop out the center seeds, leaving about 1/4-inch walls. Reserve about 1/2 cup of the chopped scooped flesh; pat it dry.

Season and pre-bake: Brush zucchini with olive oil. Sprinkle with salt, pepper, and a pinch of Italian seasoning. Place cut side up in the dish and bake for 10–12 minutes to soften slightly.

Make the Alfredo base: In a large skillet over medium heat, melt butter. Add garlic and sauté for 30–60 seconds until fragrant. Stir in heavy cream and cream cheese, whisking until smooth and lightly thickened, 3–4 minutes.

Add cheeses and seasoning: Reduce heat to low. Stir in Parmesan until melted. Add Italian seasoning, red pepper flakes (if using), a little salt and pepper, and lemon zest. Taste and adjust seasoning.

Add chicken and zucchini bits: Fold in the cooked chicken and the reserved chopped zucchini flesh. Simmer 1–2 minutes until everything is coated and warm.

Fill the boats: Spoon the creamy chicken mixture evenly into the par-baked zucchini boats. Don’t overfill to the point of spilling.

Top and bake: Sprinkle with mozzarella and a little extra Parmesan. Bake 12–15 minutes, until the cheese is melted and bubbling and the zucchini is tender but not mushy.

Finish and serve: Let rest for 5 minutes. Garnish with chopped parsley. Add a crack of black pepper and a light squeeze of lemon if you like.