1Heat oil in a large skillet over medium-high heat. Toast coriander seeds, cumin seeds, and fenugreek seeds for about 1 minute until fragrant, stirring constantly.
2Add diced onion and cook for 3–4 minutes until softened and starting to brown. Stir in minced garlic and ginger, cooking for another 30 seconds.
3Sprinkle turmeric, red chili powder, and garam masala over the onions. Stir well for 30 seconds to bloom the spices.
4Add chicken chunks and stir to coat with the spices. Cook for 3–4 minutes, stirring occasionally, until the outside of the chicken is no longer raw.
5Pour in coconut milk, diced tomatoes with juices, and chicken stock. Stir in the salt and black pepper. Bring to a simmer.
6Add cubed potatoes and stir. Reduce heat to medium and simmer, partially covered, for 20–25 minutes, until potatoes are tender and chicken is cooked through.
7Taste and adjust salt and spice as needed. Serve over rice or with flatbread, garnished with fresh cilantro.