Place the chicken breast in a large saucepan, cover with water and add one whole onion, one garlic clove, two bay leaves and salt. Heat over high heat until it boils, reduce heat to low and cover, let it cook for about 40 minutes.
To prepare the pipián salsa, heat a little bit of oil in a pan over medium heat. Add the seeds and fry until lightly browned. Then, blend together with the six tomatoes, one onion, one garlic, two serrano chillies and a little bit of pepper.
Heat a bit of oil in a saucepan over medium heat. Pour in the salsa and cook for a couple of minutes until it starts to boil. Add the chicken broth and reduce the heat to low and cook for 5 more minutes.
Add the chicken, season with salt and cook at low temperature for another 10 minutes or until flavours have mixed all together. You can cut the chicken in pieces or shred before adding to salsa for an easy taco filling.
Serve with tortillas, rice and beans.