1 wide baguette
2 tablespoons extra-virgin olive oil (EVOO), plus some for drizzling
1/2 cup freshly grated Parmigiano Reggiano
1 small onion, chopped
2 large clove garlic, divided, 1 chopped, 1 crushed
1 tablespoon tomato paste
2 cups beef stock
1 sprig of rosemary leaves, chopped
Salt and freshly ground black pepper
1/4 pound sliced roast beef
6 slices provolone cheese
Slice baguette open lengthwise just shy of actually completely splitting it open; you want it to open like a book and stay together. Then cut the bread in half so that you have 2 books. Transfer the bread to a cookie sheet and toast in the oven until golden brown, 8-10 minutes, or toast under the broiler but keep an eye on it so it doesnt burn! Once the bread is toasted, rub cut side with the crushed clove of garlic then drizzle it with a little EVOO and cover it with grated cheese.
While the bread is toasting, heat a medium-sized skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Add onion, chopped garlic, tomato paste and rosemary, season with a little salt and pepper, and cook until the onions start to get soft about 2-3 minutes. Add beef stock, bring up to a simmer and cook for 2-3 minutes to let the flavors come together.
Using tongs swish a few slices of roast beef at a time through the hot broth then transfer to the cheesy garlic bread. Once all the roast beef has been mounded on the bread, top each half with 3 slices of provolone cheese and transfer to the broiler or oven to melt the cheese.