• Rinse the chicken, discarding any extra pieces from the inside of the chicken. Pat the chicken dry with a paper towel.
• Create an even layer of the sliced onions on the bottom of the slow cooker and lay the chicken over the onions.
• Place a garlic half on each side of the chicken. Stuff two lemon halves inside of the chicken cavity. The remaining two lemon halves should be placed on each side of the chicken.
• Pour the olive oil over the chicken and rub to completely coat. Combine all of the seasonings and sprinkle over the olive oil.
• Cover the slow cooker and cook for 6 hours or until the chicken reaches an internal temperature of 165 degrees between the chicken thigh and breast without touching a bone.
• Remove the chicken and place on a serving platter. Keep warm.

To make a gravy

• Transfer the onions and about two cups of the liquid to a medium skillet. Discard the garlic and lemons.
• Place the skillet over medium-high heat. Add the wine to the chicken renderings and heat until the liquid is hot. Sprinkle in the flour, whisking until thickened.
• Carve the chicken and serve with the onions and gravy.