Bring stock to a simmer in a saucepan (do not boil). Keep warm over low heat.
Heat a Dutch oven over medium heat. Add olive oil; swirl to coat. Add pancetta; sauté 6 minutes or until crisp. Using a slotted spoon, remove pancetta from pan; drain on a paper towel. Add shallots to drippings in pan; cook 2 minutes (do not brown), stirring frequently. Stir in rice, rosemary, and garlic; cook 1 minute, stirring constantly. Add wine; cook 2 minutes or until liquid is absorbed, stirring frequently. Stir in 1 1/2 cups stock; cook 4 minutes or until liquid is nearly absorbed, stirring constantly. Add remaining stock, 3/4 cup at a time, stirring nearly constantly until each portion of stock is absorbed before adding the next (about 22 minutes total); reserve 1/3 cup stock at the last addition. Stir in pepper, truffle oil, and salt. Remove pan from heat; stir in reserved 1/3 cup broth. Top with pancetta.