Pat the short ribs dry and generously season with kosher salt, black pepper, garlic. Rub the seasoning all over the ribs until they're well coated on both sides.
Set the Instant Pot to sauté on medium-high heat. Add 1–2 tablespoons of oil, then sear the short ribs in batches on all sides until they develop a rich brown crust, about 5 minutes per side. Remove each batch from the pot and set aside.
Add 2 tablespoons of butter to the pot. Once the butter begins to bubble, add in diced carrots, celery, and onions. Sauté until fragrant and the veggies begin to soften, scrapping the bits at the bottom.
Sprinkle in 2 tablespoons of flour and cook for about 3 minutes. Then add in and 2 tablespoons of tomato paste and Beef bouillon paste to caramelize and get a rich depth of flavor. Stir until the vegetables are well coated.
Deglaze the pot with red wine, scraping up any browned bits from the bottom to release all that flavor. Bring it to a gentle boil and let the wine reduce and deepens in color.
Add in water, and return the short ribs to the pot. Season with more beef paste, onion powder, garlic powder and Worcestershire sauce, brown sugar, fresh thyme, rosemary, and bay leaves. Taste and adjust seasonings if needed.
Pressure cook on high for 60 minutes. Once done, allow the natural pressure release. Discard the herbs and place the short ribs on a plate.
Set the Instant Pot to sauté mode and bring the broth to a rolling boil for about 20-30 minutes, or until the sauce thickens. Once it thickens, add the short ribs back to the pot.
Serve over creamy mashed potatoes then ladle the sauce over the beef. Enjoy