Spread butter over the bottom of Instant Pot. Add onions, chicken, thyme, garlic, salt & pepper, potato, chicken broth, heavy cream and flour in that order, gently stirring flour overtop of mixture. Place lid on Instant Pot and make sure valve is set to seal.
Press the pressure cook button and set to high, then cook for 3 minutes. Instant Pot will take about 5-10 minutes to come to pressure then pressure cook for 3 minutes.
Meanwhile, preheat the oven to 400 F. Grease ramekins with a little bit of cooking spray. Cut out 4 small squares or circles of puff pastry using a pizza roller to fit the tops of the ramekins and set aside.
Do a quick release of the pressure on the Instant Pot by flicking the switch at the top with a spoon. Open the lid when pressure gauge has dropped and the lid opens easily.
When filling is done cooking, open lid and stir in veggies, mixing well. Divide filling among ramekins and then add piece of puff pastry. Bake on a baking sheet in the oven for 10 minutes or until pastry is golden brown. Serve and enjoy!