Heat oil in a large pot over medium-high heat.
Season both sides of the chicken well with onion powder, garlic powder, and Cajun seasoning.
Sprinkle one packet of gluten-free brown gravy mix directly over the chicken.
Sear chicken on both sides until golden; remove and set aside.
Add Trinity and minced garlic to the same pot. Sauté and scrape up all browned bits.
When onions are translucent, pour in chicken broth.
Nestle chicken back into the pot and sprinkle the second gravy packet on top.
Cover and simmer about 1 hour, until chicken is tender and falling apart.
Serve over mashed potatoes or rice.