Dice 3 chicken breasts. Measure 2 teaspoons of turmeric. Coat the chicken with half, 1 teaspoon of ground cumin and 1 teaspoon of ground coriander. Refrigerate while making the sauce.
Fry ½ chopped large onion, 2 chopped garlic cloves, and 1 chopped green chili in a little oil for 5 minutes, until browned. Add 300ml of water and simmer for 20 minutes.
Blend 400g of canned plum tomatoes until smooth. In another pan, gently fry 1 tablespoon of ground coriander, 1 tablespoon of ground cumin and the remaining turmeric in a little oil for 1 minute. Add the tomatoes and simmer for 10 minutes.
Purée the onion mixture with a stick blender, add it to the tomatoes and season with salt. Simmer for 20 minutes.
Meanwhile, fry the chicken in a little oil, stirring. Add ½ sliced large onion and 1 chopped red pepper. Cook until the vegetables soften.
Add the sauce and simmer for 10-20 minutes, until the chicken reaches 165°F / 74°C. Add water if too thick. Stir in 2 teaspoons of garam masala and 1 handful of chopped cilantro.
