If I can't find or don't have access to Tony Chachere's seasoning, what seasonings do you recommend I use to cook the brisket?
I would make a simple dry rub using onion powder, garlic powder, smoked paprika, brown sugar, chili powder, dry mustard, kosher salt, black pepper, and add some bay leaves. Rub on all sides of the brisket, wrap in plastic wrap, and allow to sit overnight.