1 14-ounce bag shredded coleslaw mix
1 cup chopped giardiniera, plus 6 tablespoons brine
1/4 cup extra-virgin olive oil
2 teaspoons sugar
3 cloves garlic, sliced
1/4 teaspoon red pepper flakes
1 1/2 cups low-sodium chicken broth
1/2 teaspoon dried oregano
1 small bunch broccoli rabe, trimmed and roughly chopped
4 6-inch sesame sub rolls, split
8 slices provolone cheese
1-pound deli-sliced low-sodium roast beef