Method
Prep:15min  ›  Cook:30min  ›  Ready in:45min 

1. Heat oil and butter in a small frying pan or wok over medium high heat. Add onion and saute until very brown, 10 to 15 minutes.
2. Add ginger and garlic to onion and saute for an additional 2 minutes. Process onion, ginger, garlic mixture in food processor until smooth. Do not rinse food processor.
3. Place onion mixture in a large saucepan. Stir in the cinnamon, black pepper, coriander, cumin, turmeric and cayenne pepper and cook over low heat until mixture is thick and has the consistency of a paste.
4. Puree tomatoes, chillies and coriander in food processor until smooth. Add to onion mixture and stir well over low heat, cooking off moisture from tomatoes and coriander. Add cream a little bit at a time, stirring constantly to avoid curdling.
5. Blend the whole mixture in food processor to puree it (for a very smooth sauce). Return to saucepan, add water and increase heat to high until sauce has heated through. Reduce heat and simmer until desired consistency is reached.
6. To serve with meat, cook the meat first separately, then simmer for 5 to 10 minutes in the sauce before serving.