French Dip Panini

Ingredients

• 1 bone in standing beef rib roast, about 3 lb.
• freshly ground pepper Kosher salt and, to taste
• 2 1/2 cups beef broth
• 1 teaspoon vegetable oil
• 1 shallot finely chopped
• 1/4 cup water
• 1 fresh thyme sprig
• 4 French sandwich rolls split horizontally
• 2 tablespoons unsalted butter melted
• 1/2 cup onion caramelized, from 1 yellow onion
• 8 ounces provolone cheese thinly sliced
• 1/2 bunch watercress