Heat the oven to 450°F and line a sheet pan with parchment.
Whisk yogurt, lemon juice, garlic, ginger, tandoori blend, cumin, paprika, turmeric, and salt in a bowl.
Add chicken and coat well. Let it stand 10–15 minutes while you prep the toppings.
Warm the oil in a skillet over medium-high heat. Sear marinated chicken until just cooked and lightly charred, 5–6 minutes.
Stir together tomato sauce, yogurt, remaining tandoori spice, honey, and a pinch of salt to make the base sauce.
Brush naan with ghee and pre-toast on the sheet pan until edges feel crisp, 3–4 minutes.
Spread sauce over naan. Top with mozzarella, cooked chicken, red onion, bell pepper, and jalapeño.
Bake until cheese is bubbling and naan is golden at the edges, 8–10 minutes.
Finish with cilantro and, if using, chutney. Rest 2 minutes, slice, and serve hot.