Very easy brisket

I came up with this recipe as an alternative to the ubiquitous onion-soup-mix recipe. It is almost as easy, and tastes much better. Don't worry about there not being any liquid added to the pan; the meat and vegetables will give off more than enough moisture as they cook. 

2 large onions, cut in half and thinly sliced (about 3 cups)

1 large carrot, peeled and chopped (about 1 1/2 cups)

1 cup golden raisins

1 cup canned chopped tomatoes

1/4 cup Dijon mustard

1 tablespoon salt

1 teaspoon freshly ground pepper

1 (4- to 5-pound) brisket