3 1/2 beef brisket (not corned beef) 1 tbsp. salt 1 tsp pepper 1 tsp garlic powder  1 tsp oregano.  4 garlic cloves (minced)  1 onion (sliced) 2 cups low sodium beef broth 3 tbsp soy sauce (or coconut aminos) 1/4 cup ketchup 1 tbsp arrowroot powder (or cornstarch) 3 tbsp cold water