Heat oil in a medium saucepan over medium heat. Stir in onions, ginger, flakes; cook, stirring, until softened, 5 minutes. Stir in tomatoes and half of reserved juice. Simmer, stirring occasionally, 15 minutes, or until tomatoes soften and sauce thickens slightly (add more juice as needed). Stir in pork and simmer 1 minute longer.
Meanwhile, cook pasta in boiling salted water according to package directions or until aldente. Drain and transfer to large serving bowl.
Toss hot pasta with Parmesan, then with sauce, and top with cilantro. Pass extra Parmesan at the table.