Step 1: Sauté the oxtails. Set your Instant Pot to the “Sauté” function. Add the vegetable oil and allow it to heat. Season the oxtails with salt and black pepper and place them in the pot. Sauté until browned on all sides, about 5-7 minutes.
Step 2: Cook the vegetables. Remove the oxtails and set aside. In the remaining oil, add the diced carrots, celery, onion, and garlic. Sauté for 3-4 minutes until softened. Add the tomato paste and mix for an additional minute.
Step 3: Deglaze the pot. Pour in the dry sherry (if using) and scrape the bottom of the pot with a wooden spoon to release browned bits.
Step 4: Add broth and oxtails. Return the oxtails to the pot and pour in the broth. Ensure the oxtails are submerged. Add thyme and bay leaf.
Step 5: Pressure cook. Seal the Instant Pot and set to “Pressure Cook” on high for 45 minutes. Let the pot naturally release steam for 15 minutes, then quick-release any remaining pressure.
Step 6: Serve and enjoy. Carefully open the lid and remove the oxtails. Serve hot, spooning broth over mashed potatoes, rice, or polenta.
Notes
Consider marinating the oxtails overnight for deeper flavor. For a thicker sauce, remove oxtails and reduce liquid on “Sauté” mode. Adding balsamic vinegar or Worcestershire sauce can enhance flavor.