1 (4-5lb) beef brisket
Table salt and ground black pepper
1 large onion, halved and sliced 1/2 inch thick
1 Tbsp. brown sugar
1 Tbsp. tomato paste with roasted garlic
1 Tbsp. paprika
1/8 tsp. cayenne pepper
2 Tbsp. flour
1 Cup chicken broth
1 Cup cooking red wine
3 bay leaves
3 sprigs of fresh thyme
2 tsp. apple cider vinegar
(1) Preheat oven to 300 degrees. Line a 9x13" pan with 24" long sheets of heavy-duty foil, positioning the sheets perpendicular to each other and allowing the excess foil to extend beyond the edges of the pan.
(2) Pat the brisket dry with paper towels. Place the brisket, fat side up, on a cutting board; using a fork, poke holes throughout the fat layer of the meat. Season both sides liberally with salt and pepper.
(3) Heat 1 tsp. vegetable oil (or bacon drippings) in a 12" skillet over medium heat until smokin. Place the brisket, fat side up in the skillet and cook until well browned, about 7 minutes. Flip the brisket and cook on the second side until well browned. Transfer the brisket to a platter.
(4) Pour off all but 1 Tbsp. of fat from the skillet; stir in the onions, brown sugar and 1/4 tsp. salt. Cook over medium heat, stirring occasionally until the onions are softened. About 10-12 minutes. Add the tomato paste and cook, stirring to combine until the paste darkens about 2 minutes. Add the paprika and cayenne. Cook stirring constantly, until well combined, about 2 minutes. Add the broth, wine, bay leaves and thyme, stirring to scrape up the browned bits from the skillet. Bring to a simmer until fully thickened.
(5) Pour the sauce and onions into the foil lined baking dish. Nestle the brisket, fat side up in the sauce and onions. Fold the foil extensions over and seal tightly. Place in the oven and cook until a fork can be inserted into the center of the brisket with no resistance, 3 1/2-4 hours.
(6) Transfer the brisket to a large bowl; set a strainer over the bowl and strain the sauce over the brisket. Discard the bay leaves and thyme from the onions and transfer the onions to a small bowl. Cover both bowls and refrigerate overnight.
(7) 45 minutes before serving preheat the oven to 350 degrees.
(8) Meanwhile transfer the cold brisket to a carving board. Discard any congealed fat from the sauce, then transfer the sauce to a medium saucepan and heat until warm, skimming any fat from the surface.
(9) While the sauce heats, slice the brisket against the grain into 1/4" thick slices, trimming away any excess fat; place the slices in a 9x13" baking dish.
(10) Stir the reserved onions and the vinegar into the warmed sauce and season with salt and pepper to taste. Pour the sauce over the brisket slices, cover the baking dish with foil, and bake until heated through, 25-30 minutes. Serve immediately.