Beef Sandwiches Au Jus

Ingredients

• 2 cups water -
• 1 tablespoon beef bouillon granules -
• 1/2 teaspoon pepper, divided -
• 1/4 teaspoon crushed red pepper flakes -
• 1/8 teaspoon garlic salt -
• 1 medium onion, thinly sliced -
• 1 small green pepper, thinly sliced -
• 4 tablespoons butter, divided -
• 1/4 teaspoon salt -
• 1 pound beef top sirloin steak, cut into 1/2-inch strips -
• 4 French rolls, split -
• 4 slices provolone cheese -