Wash the chicken pieces, drain, and place them in a large pot with the water, onion, and salt. Add more water as needed to keep enough broth. Bring to a boil over high heat, then reduce to medium and cook until the chicken is done, about 30 minutes. Reserve the broth.

On a griddle or skillet over medium-high heat, roast the chiles (pasilla or poblano), onion, and tomatillos. Roast everything well—this takes a little time, but the slightly charred flavor is unique. Toast, but do not burn!

In another pan, toast the pumpkin seeds, stirring frequently. When they start to puff up and pop, remove and set aside. In a separate pan, toast the sesame seeds, stirring often until golden—set aside.

Toast the peanuts as well, being careful not to burn them. If you can only find roasted and salted peanuts, rinse off the salt and toast them briefly.

Have a large pot ready to combine all the blended ingredients, starting with the green leaves. Blend the greens with some of the reserved broth until smooth.

Place the roasted chiles in a plastic bag to steam, then peel off the skins and remove the seeds. Blend the chiles with the rest of the green leaves.

Once all the greens are blended, pour them into the pot and set aside. Then blend the nuts and seeds.

Put everything over high heat, stirring constantly. Add more broth if needed.

Keep stirring to prevent sticking. Once it comes to a boil, reduce the heat.

Let it simmer and season with salt, keeping in mind the broth already has salt. Add the chicken and simmer for another 15 minutes.

Serve with white rice, red rice, or simply on its own.