In a large bowl, place the oyster sauce, garlic, sriracha, sesame oil, black pepper, and chicken. Massage and marinate for 30 minutes.

Heat a large saucepot and add olive oil. Sear the chicken until brown.

Add the all the remaining adobo ingredients to the pot with chicken. Bring it to a boil. Once boiling, simmer it for 30 minutes. Let it sit for 5 minutes. Reserve the adobo sauce.

Now, using to forks, pull the chicken and set aside.

In another pan, add olive oil and sauté bok choy until just wilted for 1 minutes. Add the reserved adobo sauce and cook for further 1 minute.

Assemble the tacos by adding pulled chicken into the warm tortilla. Top it with bok choy and chicharrons.