01 - Preheat the oven to 400°F and line a baking dish with parchment paper or lightly grease it.
02 - Slice zucchini lengthwise and carefully scoop out the center, leaving a half-inch shell. Chop the reserved zucchini flesh.
03 - Heat olive oil in a large skillet over medium heat. Add diced onion and sauté for 2 to 3 minutes until softened.
04 - Add minced garlic and diced bell pepper to the skillet and cook for 2 minutes. Stir in chopped zucchini flesh and cook for an additional 2 minutes.
05 - Add ground chicken to the skillet, breaking it apart as it cooks. Sauté until no longer pink, approximately 5 to 6 minutes.
06 - Stir in tomato sauce, Italian herbs, salt, and black pepper. Simmer for 3 to 4 minutes until the mixture slightly thickens. Remove from heat and allow to cool briefly.
07 - Arrange zucchini shells in the prepared baking dish and evenly fill each with the chicken mixture.
08 - Sprinkle shredded mozzarella and grated Parmesan over the filled zucchini boats.
09 - Bake for 20 to 25 minutes until zucchini is tender and cheese is golden and bubbly.
10 - Remove from the oven, garnish with chopped fresh parsley, and serve immediately.