Heat oil in a large Dutch oven or soup pot over medium heat; add onion, garlic, tomatillos, jalapeños, oregano and cumin; cook and stir until softened, about 10 minutes. Add broth and bring to simmer. Stir chicken thighs into broth and bring back to simmer. Cover and simmer 20 minutes or until chicken is very tender.
Transfer chicken to cutting board and shred into bite-size pieces with 2 forks.
With a slotted spoon, transfer cooked onion, garlic, tomatillos and jalapeños to blender. Add cilantro and 1/2 cup of the cooking liquid and blend until smooth. (I recommend using a kitchen towel instead of a lid to cover blender when blending hot liquids.)
Stir blended tomatillo mixture, shredded chicken and hominy into broth and bring to simmer over medium heat; add salt to taste. Cook and stir until heated through, about 5 minutes. Serve with desired toppings.
Video
Notes
Note the toppings are optional and not included in nutrition information.