Heat about inch of vegetable oil in an iron skillet or deep skillet on medium-high. (Just enough to cover the chicken halfway.) Have a lid nearby and a fire extinguisher when frying! Drain chicken and onions from buttermilk. Shake chicken and onions in bag with flour-spice mixture until coated.
When the oil is hot enough to make a pinch of flour sizzle, place chicken in oil and sprinkle a few of the onions in as well, being careful to not overcrowd the pan. If an onion is stuck to a piece of chicken don't separate them.....whoever gets that piece is lucky! Fry on each side about 10-14 minutes depending on how large the pieces are or until golden brown. Remove with tongs and drain on a wire rack. Remove onions as they look done (they burn easily) and drain on a paper towel. Taste an onion. If it needs more salt, add a sprinkle on the hot chicken and onions before they cool.
Before serving, add a sprinkle of chopped parsley over the chicken and onions, and serve with a side of honey, ranch dressing or hot sauce. I like this meal with a crunchy salad and some skillet cornbread. Save some chicken to eat cold the next day!