On medium low heat, add canola oil into a 5qt (or larger) pot. Once warm, add onions and cook for 4 minutes, stirring occasionally.
Add chopped garlic and cook for 1 minute, stirring occasionally.
Pour in vinegar, and let it simmer for 1 1/2 minutes. The amount of vinegar will reduce by half. Pour in chicken stock.
Add remaining ingredients, excluding the collard greens and butter. Cover, and simmer for 30 minutes.
Add collard greens, a couple of handfuls at a time, to submerge the greens into the broth. Once all greens have been submerged, turn the heat up to high to bring to a quick boil. Then, bring the temperature down to low. Cover and cook for 1 hour, stirring occasionally.
Remove the turkey neck from the pot with a fork or tongs onto a plate. Let it cool for about 5 minutes, and pick the meat off the bone. Be sure to leave behind and gristle or tendons.
Add butter and the picked turkey meat back into the pot, cover, and cook for an additional 20 minutes.
Remove from heat. Spice level can be adjusted by adding more red pepper flakes. Greens can be served right away. Enjoy!