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 4 minutes.
2. Stir in the garlic powder, vinegar, mustard, dill and broth. Scrape bottom of pot so that nothing is sticking. Turn off Instant Pot.
3. Nestle the chicken into the pot and add potatoes on top. Sprinkle the potatoes with salt and pepper.
4. Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set manual/pressure cook button to 4 minutes. When time is up let pot sit for 10 minutes and then move valve to venting. Remove the lid.
5. In a glass measuring cup add the greek yogurt. Slowly whisk the liquid from the Instant Pot into the yogurt to temper it. Whisk the cornstarch into the mixture. Stir the mixture into the Instant Pot. Turn Instant Pot to saute setting and keep it on until sauce has thickened up. 
6. Scoop onto plates and serve with a bit of parmesan cheese on top.

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 4 minutes. Transfer to the slow cooker.
2. Stir in the garlic powder, vinegar, mustard, dill, broth, chicken and potatoes. Sprinkle with the salt and pepper. 
3. Cover and cook on low for 2-3 hours, or until potatoes and chicken are tender.
4. In a glass measuring cup add the greek yogurt. Slowly whisk the liquid from the slow cooker into the yogurt to temper it. Whisk the cornstarch into the mixture. Stir the mixture into the slow cooker. Cook on high without the lid until sauce thickens a bit.
5. Scoop onto plates and serve with a bit of parmesan cheese on top.