Add the butter to the instant pot and set to saute. When its hot add the onions and baking powder. Season to taste and cook for around 10 minutes.
Add the garlic followed by the stock.
Deglaze the pot if necessary and add the chicken. Add all of the herbs.
If your serving with garlic bread, put this in the oven now.
Stir everything together and then put the lid on the pot. Set on high pressure for 7 minutes.
Leave under pressure for a further 7 minutes and then do a quick release.
Use a slotted spoon to remove the chicken and onions to an ovenproof dish. Layer over the Swiss cheese and place under the grill to melt (broil).
Whilst the cheese is melting, set the pot to saute. remove around 3 tablespoons of liquid to a bowl and add the cornstarch. Mix well together and add back to the pot to thicken.
Serve over garlic bread with the chicken and onion mixture on top followed by the thickened sauce.
Video
Notes
If you don't like garlic bread it will be perfect served with rice or just crusty bread.