Grind the ginger, peppercorns, turmeric powder, onions and green chilies to make a coarse paste. Wash the potatoes. Add salt and turmeric powder & boil them with skin. Then peel of the skin and cut into halves. Heat oil and ghee in a large pan and add mustard seeds. When it pops add cinnamon, bay leaves & cloves. When it turns brown add garlic and curry leaves. After a few seconds add the onion, ginger and chili paste. Fry for a couple of minutes. Then add the chicken pieces and fry. Add potatoes, carrots, garam masala and salt. Cover the pan and cook for 5 minutes. Then pour the coconut milk and add the green peas. Cover and cook until the chicken is fully cooked.