Mix onion powder, garlic powder, and pepper. Pat dry chicken and season both sides with the seasoning mix.
Switch on Instant Pot and set to saute mode. When the inner pot is hot enough, add 1 teaspoon of oil.
Place the seasoned chicken breast in a single layer and cook it for 2 minutes, turn it and fry it for another 1 minutes.
Remove the chicken and keep it aside.
Add chicken stock to the pot. Scrap the bottom to release any brown bits.
Add crushed bouillon cube, thyme, parsley, remaining seasoning, and chicken breast to the pot.
Close the lid, seal the valve, and set the pot to manual mode/-high pressure mode. Cook on high pressure for 5 minutes.
Once the timer is off, let the pressure release naturally for 5 minutes, and then release the rest of the pressure manually.
Take out the cooked Chicken breast from the pot and keep it covered with a foil.
Empty all the stock from the pot, strain it in a colander.
Keep the empty inner pot back and switch the Instant pot to saute mode again.
Melt butter and add flour to it. Saute the flour until it's bubbly, the raw smell is gone but the flour is not browned.
Add back the strained stock slowly back to the pot. Keep stirring the mixture to avoid any lump. The gravy will start to thicken.
Shredd or make thin slices of chicken. Add it to the gravy.
Serve over mashed potato or rice.