The night before baking, remove your brisket from the package and dry it off with paper towels. Then you are going to place it, fatty side up, in a roasting pan. Be sure to use a roasting pan that just fits the brisket. You do not want to have a lot of room to spare.

Rub the fatty part with the cooking oil, just a tablespoon or so. Then season the brisket all over the top with the garlic salt, black pepper, and onion powder. Place the brisket in the fridge overnight, uncovered. This is so the fat cap dries out and you can get a nice caramelization on it when baking.

When you are ready to bake, take the brisket from the fridge at least an hour before baking and let it come to room temperature. Set your oven to 375° and let it heat.

Chop up the carrots, onions, and celery and place around the brisket and cut the butter into smaller pieces and place all over the veggies.

Make your stock by mixing the two cans of 7UP with the ketchup and the packet of onion soup mix. Whisk until well combined. Use caution, this will foam up some.

Place the brisket in the oven, uncovered, and without the stock you made for one hour. The top should caramelize a bit while it bakes. At the one hour mark, reduce the temperature to 325° and pour the stock you made all over the brisket and the vegetables. Cover the roasting pan with a piece of foil then bake the brisket for 45 minutes per pound.

In the last 45 minutes uncover the pan, use a ladle or spoon to spoon some of the drippings over the top of the brisket, and finish baking.

Turn off the oven at the end and let the brisket rest in the oven for 20 to 25 minutes before slicing.

When ready to slice you can carefully remove the brisket to a cutting board. Then you can either strain the drippings into a sauce pan or add the veggies as well. You can serve the veggies on the side if you like.

Bring the drippings to a simmer, you can strain off some of the fat and grease if you like. Let this simmer for 10 minutes. You can then use an immersion blender to blend up the carrots, onions, and celery until smooth if you like, or leave them whole. Slowly add the corn starch and water mix while whisking and simmering so that the drippings thicken up into a nice gravy.

Serve the slices with the gravy. This also makes great sandwiches.