Place flank steak into a slow-cooker with the quartered onion and bay leaves. Cover with cold water and cook on high for 4-6 hours, or until the meat can be shredded easily. Remove meat from pot and discard water and veggies.
Shred the steak with a fork and transfer to a medium-size mixing bowl. Add red onion, 2 cloves garlic and green chile to the bowl and combine. Season with salt and pepper and reserve.
Place a large skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Add the chorizo to the pan and cook until golden brown, 15-16 minutes. Add the shredded meat and veggie mixture to the pan, spreading it out to cover the entire bottom, and cook until crispy on the bottom. Flip the mixture over and cook on the other side until crispy, about 15 minutes per side.
While the meat is cooking, place a medium pot over medium-high heat with 1 turn of the pan of EVOO, about 1 tablespoon. Add the remaining chopped onion, garlic, chopped tomatillos, and cumin to the pan, and cook until the veggies are tender and the tomatillos have begun to release their liquids, about 8 minutes. Transfer the mixture to a food processor, add in the honey, avocado and cilantro and pulse to puree.
To serve, spoon some of the meat and veggie mixture in soft flour tortillas and top with the salsa verde.