01 - Preheat oven to 400°F.
02 - Slice zucchinis in half lengthwise. Scoop out the centers with a spoon, leaving about 1/4-inch thick shells. Reserve some of the inner flesh and chop.
03 - Brush zucchini boats with olive oil and sprinkle with salt and pepper. Place on a baking sheet.
04 - In a large skillet over medium heat, melt butter. Sauté onions until soft, about 3 minutes. Add garlic, ginger, and reserved chopped zucchini flesh. Cook 2 minutes more.
05 - Add diced chicken to the skillet. Cook, stirring, until browned on all sides, about 5–6 minutes.
06 - Stir in tomato purée, garam masala, cumin, coriander, chili powder, turmeric, salt, and pepper. Simmer for 8 minutes, stirring occasionally.
07 - Reduce heat to low. Add cream and Greek yogurt, stirring until the sauce is creamy and the chicken is fully cooked. Simmer another 2–3 minutes. Adjust seasoning.
08 - Fill each zucchini boat with butter chicken mixture. Top with mozzarella, if using.
09 - Bake in preheated oven 18–20 minutes, or until zucchini is tender and cheese is golden.
10 - Remove from oven and top with fresh cilantro and mint. Serve warm.