Season the short ribs generously with salt and pepper on all sides. Heat the olive oil in a large Dutch oven over medium-high heat and sear the ribs in batches until browned on all sides. Remove the ribs and set aside.

Add the onion, carrots, and garlic to the pot. Cook for 5 minutes until the vegetables soften. Pour in the red wine and scrape the bottom to release any browned bits. Let the wine simmer for 3 minutes.

Return the ribs to the pot and add the beef broth, thyme, and bay leaves. Bring to a simmer, then cover and cook on low heat for 2.5 to 3 hours until the meat is very tender.

While the ribs finish, make the polenta. Bring the water to a boil in a medium saucepan and add a pinch of salt. Whisk in the polenta gradually. Reduce heat to low and cook for 20 minutes, stirring often. Stir in the heavy cream, butter, and Parmesan until smooth.

Remove the ribs from the pot. Strain the braising liquid if desired, then simmer it uncovered for 10 minutes to thicken into a sauce. Serve the ribs over the polenta and spoon the red wine sauce on top.