How to make slow cooker roasted garlic chicken

The recipe below originated in the south of France, in a region heavily influenced by Italian and Mediterranean flavors. Using an entire head of garlic seems like an overpowering choice, but the garlic mellows and sweetens greatly during the extended cooking time until it’s almost caramelized. This dish is guaranteed to become a new favorite.
Old-fashioned versions of this dish call for vermouth and tarragon, which tend to produce a flavor that’s a bit too much like licorice for modern tastes. Here a splash of white wine and sprinkle of marjoram keep the herbaceous quality and subtle sweetness. The garlic cloves are soft and buttery after cooking and taste great as a spread, stirred into veggies, or used to make mashed potatoes (learn how in the Pro Tip at the end of the recipe).
1 tablespoon (15 ml) olive oil
3 1/2 lbs. (1.6 kg) bone-in, skin-on chicken thighs
2 teaspoons (14 g) salt
1 teaspoon (1 g) dried marjoram
1/2 teaspoon (1 g) pepper
1 large onion thinly sliced 
1 medium bulb garlic
2 tablespoons (30 ml) white wine
1 tablespoon (1 g) fresh parsley, finely chopped
Pat chicken breasts dry and rub all over with oil.
Mix salt, marjoram, and pepper in a small bowl and sprinkle evenly over chicken, coating both sides.
Arrange onion slices evenly over the bottom of a 6-quart slow cooker. Lay chicken on top.
Separate garlic cloves, but do not peel. Arrange around chicken. Drizzle wine on top.
Cover and cook on low for 8 hours. Remove garlic cloves and reserve for another use. Serve chicken and onions sprinkled with parsley, alongside juices from the slow cooker.
Pro Tip: The perfect side for this chicken is mashed potatoes made with the roasted garlic. Boil 2 lbs. cubed and peeled potatoes for 15-20 minutes in boiling salted water. Drain and add 2 tablespoons butter, 1 cup of milk, and the reserved garlic, squeezing each clove from its husk. Mash together and season to taste with salt and pepper.