In a skillet, warm up 2 tablespoons of olive oil over medium heat. Add the diced onion and sauté until it's softened and translucent, about 5 minutes.

Next, stir in the minced garlic, ginger, garam masala, salt, black pepper, cayenne pepper, and any spices you choose. Cook this fragrant mixture for 1-2 minutes until the aromas fill your kitchen.

In your crockpot, combine the chicken thighs with the sautéed onion and spice mixture. Stir well to make sure all the chicken is coated in those flavors.

Pour in the 29 oz can of tomato puree and gently mix together with the chicken. Add the bay leaves, allowing the sauce to infuse with their earthy flavor.

Next, blend the yogurt and heavy cream into your mixture. Stir until everything is well combined, then cover your crockpot.

Cook on low for about 6-8 hours or on high for 3-4 hours. The chicken should be tender and the sauce flavorful and thickened by the time it’s done.

If you prefer a thicker sauce, mix 3 tablespoons of cornstarch with a bit of water to create a slurry, then stir it into the crockpot and let it cook for another 15-30 minutes.

Before serving, adjust the seasoning with salt and lemon juice based on your taste. Garnish with chopped fresh parsley or cilantro to brighten the dish.