01 - Preheat oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - Slice zucchini lengthwise and scoop out the centers, leaving a 1/2-inch shell. Chop reserved zucchini flesh and set aside.
03 - Heat olive oil in a large skillet over medium heat. Sauté diced onion for 2–3 minutes until softened.
04 - Add minced garlic and diced red bell pepper; cook for 2 minutes. Stir in chopped zucchini flesh and cook an additional 2 minutes.
05 - Add ground chicken, breaking it up as it cooks. Sauté for 5–6 minutes until no longer pink.
06 - Stir in tomato sauce, dried Italian herbs, salt, and black pepper. Simmer for 3–4 minutes until slightly thickened. Remove from heat and let cool briefly.
07 - Place zucchini boats in the prepared baking dish and evenly spoon the chicken mixture into each boat.
08 - Sprinkle mozzarella and Parmesan cheese over the filled zucchini boats.
09 - Bake for 20–25 minutes until zucchini is tender and cheese is golden and bubbly.
10 - Garnish with chopped fresh parsley before serving.