Step 1: Toast Whole Spices

In a large pot or rondeau over low heat, add vegetable oil, cardamom pods, cinnamon sticks, crushed coriander seeds, whole cloves, and cracked black peppercorns. Stir and toast until the spices become aromatic.

Step 2: Caramelize Onions

Thinly slice the red onions and add them to the pot with the toasting spices. Cook over low to medium-low heat, stirring occasionally, for 30-40 minutes. The onions should become very soft, deeply caramelized, and golden brown.

Step 3: Add Aromatics and Spices

Add the finely minced garlic and ginger to the caramelized onions and cook for 2-3 minutes until fragrant. Deglaze the pan with a splash of water, scraping up any browned bits from the bottom. Add the turmeric, ground coriander, cumin, and chili powder. Stir and cook for another minute.

Step 4: Make Tomato Base

Puree the fresh tomatoes in a blender to a semi-chunky consistency. Pour the pureed tomatoes into the pot with the onion and spice mixture. Continue to cook on low heat for 30-45 minutes, stirring occasionally, until the mixture reduces, thickens to a paste-like consistency, and most of the moisture has evaporated.

Step 5: Season the Curry Base

Once the curry base is thick and concentrated, season it generously with sea salt and mix well. The base is now complete and can be used immediately or stored.

Step 6: Cook the Chicken

In a separate large pan, heat vegetable oil over high heat. Add the diced chicken breasts and cook for 7-8 minutes, stirring frequently, until the chicken is cooked through and lightly browned on all sides. Season with sea salt.

Step 7: Combine and Finish Curry

Add about 1 1/2 cups of the prepared curry base to the cooked chicken. Stir everything together until the chicken is well-coated. Add the freshly chopped cilantro (fresh coriander) and mix to combine.

Step 8: Serve

Serve the authentic Indian chicken curry hot. It is traditionally served in a tiffin box with sides like long-grain rice, steamed vegetables, and naan bread.

• Properly caramelizing the onions for 30-40 minutes is crucial for developing a deep, rich, and sweet flavor base for the curry.

• Deglaze the pan with a little water after cooking the aromatics to lift the 'fond' (browned bits) from the bottom, which adds significant flavor.

• The curry base can be made in a larger batch and stored. It lasts up to 5 days in the refrigerator or can be frozen for up to 2 months.

• For a thinner curry, cook the tomato base for less time. For a thicker, more concentrated curry, cook it down longer until it's paste-like.

• Dark meat chicken can be used as a substitute for chicken breasts.

• Instead of pureeing fresh tomatoes, you can use canned tomatoes or pre-chopped tomatoes.