1.Preheat oven to 325 degrees.
2.Mix together soup mix, water, ketchup, garlic and black pepper, sugar if using until combined.
3.Pour into pan, lay brisket over sauce then turn over a few times to coat the brisket.
4.Lay sliced onions over brisket.
5.Cover pan with aluminum foil, not too tight.
6.Bake for about 3 hours or until brisket is tender.
7.Let sit in the pan for about 15 minutes before slicing. Enjoy!!