Break the cinnamon stick into smaller pieces and, together with the cardamom, cloves and pepper, crush them finely in a mortar (or grind them in a coffee grinder). Place in a bowl. Add fresh coriander, curry leaves, lime juice, chili, ginger, garlic, tamarind juice as well as turmeric and mix everything to a paste. Season to taste with salt. Coat the chicken breasts with the paste and let rest for about 20 minutes. Meanwhile, preheat the oven to very hot (220-240 degrees). Now drizzle the chicken fillets with oil, place in a suitable roasting dish and bake in the preheated oven for 20 minutes without turning the breasts over. Arrange on plates and serve.