In a large pot over medium-high heat, cover potatoes with a pinch of salt and just enough water to cover them; bring to a boil. Once cooked through, drain but save 1/4 cup potato water. Return potatoes to pot, pour in 1/2 of the cooked potatoes. Mash until smooth, adding more potato water to desired consistency. Stir in garlic powder, salt and pepper.

 

Cook chicken thighs with slow cooker sauce in a slow cooker according to package directions, about 8 hours. 

 

Serve hot with garlic mashed potatoes alongside.