1. Puree the ginger, garlic, lemon juice, and 2 tablespoons of olive oil in a food processor. Thin with water if needed. Pour over the chicken, cover, and refrigerate while you proceed.
2. Puree all the sauce ingredients in a food processor until smooth. Set aside.
3. Heat remaining oil in a large, heavy-bottomed pot over medium heat. Add the onions and saute until slightly translucent (5 minutes).
4. Stir in the marinated chicken and the tomato paste. Saute until fragrant and browned (5-6 minutes).
5. Stir in the korma sauce, yogurt, cauliflower, raisins, cashews, and salt. Simmer for as long as you can before eating so the flavors can develop. Thin with extra water as needed to maintain your preferred consistency.
6. Serve hot over rice.