Turn the Instant Pot on sauté mode. Put butter (or fat from drippings) into the inner pot and cook until butter is melted and starts to bubble.
Stir flour into butter until it's well combined and not lumpy. Add in the fresh herbs, if you're using them.
Slowly stir in the pan drippings/stock, making sure the roux and liquid are well combined and smooth. Turn sauté mode off.
Close the Instant Pot lid and seal pressure valve. Cook on manual high pressure for four minutes.
Use a quick pressure release, remove the lid, and stir gravy.
If additional thickening is desired, turn back on to sauté mode and cook for 1-2 minutes.
Notes
Make your own stock for this recipe, or you can use pre-made chicken stock. How to make gravy from drippings:First remove the bird from the pan. Pour the juices from the hot pan into a heat-safe measuring cup. Allow to sit until the fat rises to the top. Use a ladle to scoop the fat into a separate container. Measure four tablespoons of drippings into the pan in place of butter. Measure the remaining drippings and add enough broth to make four cups.Making gravy from scratch on the stove top:If you've roasted your turkey or chicken in a flame-safe roasting pan, you can make your gravy right in that. Alternatively, use a sauté pan or deep frying pan for this. Measure four tablespoons of fat (pan drippings or butter) into the roasting pan. Set the pan over medium heat until fat is hot. Stir in flour using a whisk, mixing it well until the flour is completely combined with the fat and a bit bubbly. Slowly begin to pour the pan drippings/broth into the hot pan, mixing the liquid with the roux. This is where you want to really take your time, making sure the liquid combines with the roux to prevent lumps in your homemade gravy. Once the roux and liquid have become one, you can add liquid a bit more quickly. Continue stirring with the whisk until all of the liquid is added. Simmering for about five minutes will thicken the gravy further.