In your slow cooker, add the chicken thighs along with the whole-milk plain yogurt and kosher salt. Stir gently to ensure every piece of chicken is evenly coated with the yogurt marinade.

In a skillet over medium heat, add a splash of oil and toss in the finely diced yellow onion. Sauté for about 8 minutes until the onions become tender and translucent.

Once the onion is clear and aromatic, introduce minced garlic, grated ginger, and your ground spices. Cook this fragrant mixture for 2-3 minutes, stirring continuously.

Next, add tomato paste and the drained diced tomatoes to the skillet. Stir well, allowing the mixture to simmer for about 2 minutes.

Carefully transfer the aromatic sauce from the skillet into the slow cooker, mixing it thoroughly with the marinated chicken.

Cover your slow cooker and cook on HIGH for 4 hours or on LOW for 8 hours.

About 10-15 minutes before you're ready to serve, stir in the heavy cream or coconut milk.

If you prefer a thicker sauce, uncover the slow cooker and continue cooking on HIGH for an additional 30 minutes.

Before serving, squeeze fresh lime or lemon juice over the finished dish to brighten the flavors.