1. In a covered medium saucepan, combine 2 cups diced yellow onions with 1 cup water. Bring water to a boil and cook about 10 min, until onions are soft.
2. Puree the onions and cooking liquid.
3. In a bowl, mix the pureed onions with 1 cup yogurt.
4. Puree 1 cup pistachios, 1/2 cup chopped green bell pepper, 2 chopped Thai chilies, 1/2 cup chopped cilantro, and 1 cup water.
5. In a large saucepan, heat 2 Tbsp canola oil, stir in 1 Tsbp ginger-garlic paste (see CTM recipe), and cook for 30 seconds before adding the onion-yogurt mixture.
6. After that all comes to a boil (about 5 min), add the pistachio puree and 1/8 tsp turmeric and cook for 5 min.
7. Reduce heat to medium an add 2 Tbsp butter and 1/2 cup heavy cream.
8. Add 2 lbs chicken, 2 1/2 tsp salt, and 1 tsp ground cardamom and cook for about 15 minutes.