On a large platter, combine the flour with 1 tsp of salt and ½ tsp of black pepper. Dredge the ribs in the flour, coating all over.
Select SAUTÉ on High and add the oil. When the oil is shimmering, and working in batches, sear the ribs until browned all over. Remove from the Instant Pot and set aside.
Add the pancetta and cook until crisp, about 4 to 5 minutes. Add the onions and carrots and cook until soft, another 5 minutes. Stir in the garlic and cook for 1 minute.
Stir in the tomato paste and red pepper flakes and cook for 1 minute.
Pour in the wine and bring to a boil.
Add the broth, vinegar, 1 tsp salt, ½ tsp black pepper, and the red pepper flakes, and oregano. Stir to combine.
Nestle the seared ribs and herbs into the sauce. Lock the lid into place and then select PRESSURE COOK on High and set the timer for 40 minutes. Make sure the venting valve is closed.
Once finished pressure cooking, allow to steam naturally for 10 minutes, and then release the remaining steam by turning the steaming valve to open.
Remove the ribs and select SAUTÉ on High and bring the sauce to a simmer. Use a spoon or small ladle to remove grease that is pooling along the side of the pot.
Serve ribs over warmed polenta or mashed potatoes with sauce drizzled on top.