Season oxtail with green seasoning or your preferred blend.
If using an Instant Pot, select the Sauté function (see notes for regular slow cooker).
Add 1 tablespoon of coconut oil and heat.
Brown the oxtail in a single layer, turning to sear both sides.
Remove the oxtail once browned. Repeat if needed to brown all pieces.
Add remaining coconut oil to the pot, then sauté onions, celery, and garlic until translucent.
Add ¼ cup of stock and stir well to deglaze.
Return oxtail to the pot and stir to coat.
Add remaining stock, carrots, sweet potatoes, tomato paste, pimento peppers, bouillon cube, black pepper, and all-purpose seasoning.
Pour in water until it covers the meat by at least 1 inch (see notes).
Add salt to taste.
Add scotch bonnet pepper (whole) and optional hot pepper if using.
Cover and switch the Instant Pot to Slow Cooker mode. Set for 7 hours on low, or until meat is tender.
About 1 hour before done, stir in flour to slightly thicken the soup.
Once meat is tender and soup is flavorful, serve hot.