Rub 3 tablespoon of steak seasoning into beef brisket coating the meat evenly with seasoning. Let marinate for at least 4 hours or overnight.
Preheat oven to 350°F.
In a cast iron skillet sear all sides of the brisket with 2 tablespoon of butter, about 5 minutes per side.
Clean and slice all 4 onions and caramelize them in the same skillet with 3 tablespoon of butter.
Once the meat is seared, place in the same cast-iron skillet or a dutch oven with fat side up and top with caramelized onions. Then, add in the remaining ingredients 6-8 garlic cloves, 2tbsp Worcestershire sauce, and 2 cups beef broth. cover tightly with lid or foil and cook in preheated oven at 350F for 3-4 hours or until tender and fall apart.
Keyword beef, BRISKET, DINNER, holiday dessert, main dish, meat, onions