Peel the onion and chop into 1- to 2-inch chunks. Add to a pot along with 1 cup of water. Boil uncovered until almost all water has evaporated. Let cool for a bit.

Transfer the boiled onion along with any remaining water into a food processor and process into a puree. Set aside.

Combine ginger, turmeric, curry powder, chili powder and garlic in a small bowl.

Stir 3 tablespoons of water into the spices and mix with a spoon to make a paste. Set aside.

Heat the vegetable oil in a Dutch oven until shimmering. Sear the chicken thighs on both sides in the hot oil.

Turn the heat down, then move the chicken thighs over to one side of the Dutch oven. Add fenugreek, cumin, coriander and mustard seeds to the other side. Fry the seeds for 4 to 5 minutes. (The seeds need to sizzle but be careful not to burn them.)

Carefully add the onion puree, then the star anise and the carrot.

Turn the heat back up a bit and fry the onion and carrot for 10 minutes. Remove the star anise and discard.***

Add the spice paste, crushed tomatoes, tomato paste and chicken broth and mix well. Let the mix come to a boil, then transfer to the slow cooker. Cook on low for 3 hours.

Stir in the sour cream, then season to taste with a little bit of salt.

Serve the curry with naan or rice and sprinkle with cilantro.

For extra flavor, fry one egg per serving (sunny side up or over easy) and serve on top of the curry.