bring 12 cups (2.8 liters) wate rto a boil in a 5-to 6 quart (5- to 6 liter) pan over medium-hig heat. Stir in pasta and cook just until tender to bite (8 to 10 minutes); or cook according to package directions. Meanwhile, combine cream, onions, basil, tomatoes, and white pepper with juice in frying pan. Bring to a boil over medium-high heat and cook, stirring, for 1 minute. Stir cornstarch mixture and add to pan. Return mixture to a boil and cook, stirring, just until slightly thickened. Remove from heat, stir in vermouth and shrimp.