Season the ribs with flake salt on all surfaces. Allow the salt to pull out the excess moisture for 15 minutes.
Heat a cast-iron skillet on high to the point of smoking. Pat the meat dry with paper towels to absorb the excess moisture. Sear the ribs on all sides.
Remove the ribs from the pan and allow to cool on a clean plate.
Place the cooled short ribs in a vac and seal bag and remove all the air or a gallon zip-top bag and use water displacement to remove the air from the bag before clipping it to the side of the sous vide container.
Set the sous vide water to 155 F and cook for 48 hours.
If not eating the short ribs at the end of the cook, plunge the closed bag into an ice bath to chill them down. Finish the meat and make the sauce when you are ready to eat.
Finishing the meat and making the wine sauce.
Remove the cooked short ribs from the sous vide bag, reserving the juices in the bag to make the wine sauce.
In a heavy bottom or cast iron pan, sauté the onions and garlic until they are soft and start to take on a bit of color.
Dust the flour to the cooked onions and garlic and stir for 1 minute. This will make a roux and help thicken the sauce.
Deglaze the pan with the purge, or juices, from the bag scraping the bits from the bottom of the pan.
Add the wine to the pan, stirring to combine, bring to a simmer and reduce until thickened. About 4 minutes.
Add the butter to the sauce and stir until melted and incorporated.
Transfer the sauce to a serving dish, straining it through a fine-mesh strainer to remove the onions from the sauce.
Pat the meat dry with paper towels. Heat a heavy bottom or cast iron pan over high heat to the point of smoking.
Sear the short ribs for 1 minute on all sides to get an amazing crust.
Serve with the red wine reduction sauce.
Can I use boneless short ribs for this recipe?Absolutely, yes! Boneless short ribs will work well for this recipe. But know that a bone will give you an extra layer of flavor to the meat and a bit more stability when searing the beef.Can these ribs be made ahead?These short ribs can be cooked up to a week ahead of serving. Just be sure to properly cool them down before storing them in the refrigerator.