Instant Pot Instructions:

1. Turn Instant Pot to saute setting. When display says HOT add in the butter and let it melt. Add in the onions and mushrooms and saute for 5 minutes. Add in the parsley, tarragon, garlic powder, salt and pepper. Stir to coat the mushrooms.
2. Pour in the broth and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot. 
3. Add in the chicken evenly. 
4. Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set the manual/pressure cook button to 4 minutes. When time is up let pot sit for 5-10 minutes and then move valve to venting and remove the lid. 
5. In a small bowl stir together 3 Tbsp of cornstarch with equal parts cold water until smooth. Turn Instant Pot to saute setting. Stir in the cornstarch slurry to thicken mixture. Turn off pot.
6. Stir a cup of the hot liquid from the Instant Pot into the cream to temper it then stir it into the pot along with the vinegar. 
7. Serve chicken, mushrooms and sauce over mashed potatoes, rice or noodles.

Slow Cooker Instructions:

1. Heat a pan over medium high heat. Add in the butter and let it melt. Add in the onions and mushrooms and saute for 5 minutes. Add in the parsley, tarragon, garlic powder, salt and pepper. Stir to coat the mushrooms. Transfer to the slow cooker.
2. Add in the broth and the chicken.
3. Cover and cook on low for 2-3 hours. 
4. In a small bowl stir together 3 Tbsp of cornstarch with equal parts cold water until smooth. Turn slow cooker to high setting. Stir the cornstarch slurry into the slow cooker and let it cook without the lid for about 10 minutes. 
5. Stir a cup of the hot liquid from the slow cooker into the cream to temper it then stir it into the slow cooker along with the vinegar. 
6. Serve chicken, mushrooms and sauce over mashed potatoes, rice or noodles.