Preheat oven to 300°F.
Remove brisket from packaging and fully dry with paper towels.
Combine flour, salt and pepper together. Fully coat brisket with flour mixture.
Place a Dutch oven or deep roasting pan on the stovetop at medium heat, once pan begins to smoke add oil.
Sear all sides of brisket. Remove from Dutch oven and set aside on dish.
Keep Dutch oven on the heat and add aromatics, sauté for 3 minutes.
Add ½ cup of red wine and tomato paste to aromatics. Scrap the bottom of the pan and reduce liquid for 3 minutes.
Place brisket on top of aromatics and add remaining braising liquid. Bring to a simmer.
Cover and place in oven for 2 hours.
After 2 hours brisket will still be a little tough, perfect for slicing. Remove brisket and set on cutting board, let the brisket rest for 5 minutes before slicing.
While brisket rests prepare the sauce.
Remove thyme sprigs, bay leaf and 1 cup of liquid. Do not discard reserved liquid.
With an emersion blender, blend the remaining liquid with carrot, celery and onion. If sauce looks too thick add some of the liquid that was reserved. Season to taste.Chef Tip: No emersion blender no problem, use a stand blender and pour liquid back into Dutch oven. Slice brisket against the grain and carefully place brisket in Dutch oven with sauce.
Cover and return to oven for 1 hour. Let brisket rest for 20 minutes before serving. Enjoy!