Set Instant Pot to saute. Add olive oil and sugar, letting sugar caramelize.
Sear oxtails in batches, seasoning with salt and pepper. Set aside when browned.
Saute garlic, then add shallots and onions until translucent.
Add chicken stock, tomato paste, potatoes, and carrots.
Return oxtails, pour in red wine, add herbs (parsley, rosemary, bay leaves).
Close Instant Pot and set to stew/high pressure for 35 minutes.
After cooking, switch to saute and simmer a few more minutes.
Garnish and serve with white rice and fried plantains.