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. 
2. Pour in the broth and vinegar and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot.
3. Stir in the chicken. Sprinkle the chicken with poultry seasoning, salt, pepper, rosemary and garlic powder.
4. Cover Instant Pot and secure the lid. Make sure valve is set to 3 minutes. When time is up let pot sit for 5 minutes and then move valve to venting. Remove the lid. 
5. In a small bowl stir cornstarch together with 1 Tbsp of cold water until smooth. Then turn Instant Pot to saute setting. Stir the slurry into the pot to slightly thicken the sauce. Turn off Instant Pot.
6. Serve chicken, mushrooms and sauce over the top of mashed potatoes or rice. 

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. Transfer to slow cooker.
2. Stir in broth, vinegar, chicken, poultry seasoning, salt, pepper, rosemary and garlic powder.
3. In a small bowl stir cornstarch together with 1 Tbsp of cold water until smooth. Stir the mixture into the slow cooker.
4. Cover and cook on low for 2-3 hours.
5. Serve chicken, mushrooms and sauce over the top of mashed potatoes or rice.