Once your Beef Shanks are cooked, remove them and set aside.
Save 1 cup of the Broth.
Peel and rinse the tomatillos. Then chop them into quarters. Set them aside.
Chop the Onions. Mince the garlic.
Chop the Pasilla Chili into 3 strips, taking the seeds out.
Heat a pot over medium heat. Then add the oil and saute the onions and the garlic. Then, add the tomatillos. Stir.
After approx. 10 minutes, the tomatillos color should darken. Now, add the broth, thyme, Guajillo Chili, salt, pepper and sugar. Cook it and don't forget to stir occasionally.
After aprox. 20 minutes, the broth should reduce and the tomatillos will break completely, melting with the onions and garlic. Add the Beef Shanks and cook for approx. 15 minutes or until the consistency looks creamy.
Taste for seasoning.
Let rest 10 min. before serving and remove the Thyme sprigs and the Guajillo Chili skins.
Serve it with garlic white rice and enjoy!