1 . Stage
In a large skillet over medium-high heat, heat 1 tablespoon oil. Add chicken, season with salt and pepper, and sear until golden, 3 minutes per side.
2 . Stage
Meanwhile, in a large slow cooker, toss potatoes with remaining 2 tablespoons oil, butter, garlic, thyme, parsley, and Parmesan and season generously with salt and pepper. Add chicken and cook on high for 4 hours or low for 8 hours, until potatoes are tender and chicken is fully cooked.
3 . Stage
Garnish with Parmesan before serving.