Place the tomatillos, jalapeños, half the onion, garlic, and cilantro in a blender. Blend until smooth to make the verde sauce.
Heat a large pot over medium heat. Add the chicken thighs and cook until lightly browned on both sides, about 4 minutes per side.
Pour the blended verde sauce into the pot with the chicken. Add the chicken broth, oregano, cumin, and a pinch of salt and pepper. Bring to a simmer.
Cover and cook for 20 minutes, until the chicken is cooked through. Remove the chicken, shred it with two forks, and return it to the pot.
Stir in the hominy and collard greens. Simmer uncovered for 10 minutes, until the greens are tender but still bright.
Taste and adjust salt and pepper if needed. Serve hot with lime wedges and sliced radishes on the side.