Heat a large skillet over medium heat. Add a small amount of oil or butter.
Add onion and bell pepper. Sauté **3–5 minutes** until soft.
Add garlic paste and cook **30–45 seconds only** until fragrant. Do not let it brown.
Sprinkle in flour and stir constantly for **1–2 minutes** to cook out the raw flour taste.
Slowly whisk in chicken stock, then beef stock. Stir until smooth.
Season with black pepper, garlic powder, onion powder, Cajun seasoning, and salt. Bring to a gentle boil.
Reduce heat to low and let gravy simmer **5 minutes** until thickened.
Add chicken pieces to the gravy, spooning sauce over the top.
Cover and simmer on low **25–30 minutes**, flipping chicken once so it absorbs the gravy.
Taste gravy and adjust seasoning if needed.