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 shallot and mushrooms and saute for 4 minutes. 
2. Pour in the broth and vinegar and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot. 
3. Add in the cubes of chicken. Sprinkle the chicken with the salt, pepper and garlic powder. 
4. Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set the manual/pressure cook button to 3 minutes. When time is up let pot sit for 5-10 minutes and then release remaining pressure and remove the lid. 
5. In a small bowl stir together cornstarch with about 3 Tbsp of cold water until smooth. Turn Instant Pot to saute setting and stir the slurry into the pot until sauce thickens. Turn Instant Pot to the keep warm setting. 
6. Stir in the heavy cream, lemon juice and zest. 
7. Serve chicken, mushrooms and sauce over rice or mashed potatoes. 

Slow Cooker Instructions:

1. Heat a pan over medium high heat. Add in the butter and let it melt. Add in the shallot and mushrooms and saute for 4 minutes. Transfer to the slow cooker. 
2. Add in the broth, vinegar, cubes of chicken, salt, pepper and garlic powder. 
3. Cover and cook on low for 2-4 hours. 
4. In a small bowl stir together cornstarch with about 3 Tbsp of cold water until smooth. Stir the slurry into the slow cooker and let thicken for about 10 minutes on the high setting.  
5. Stir in the heavy cream, lemon juice and zest. 
6. Serve chicken, mushrooms and sauce over rice or mashed potatoes.