Cook pasta according to package directions, omitting salt and fat.
Drain.
Melt butter in a medium saucepan over medium heat.
Add onion and garlic; cover and cook 3 minutes or until tender.
Add tomato sauce; simmer, partially covered, 8 minutes or until thick.
Combine flour and water, stirring with a whisk until smooth.
Add flour mixture to pan; cook 1 minute.
Add half-and-half, milk, vodka, salt, and pepper; bring to a boil. Stir in cheese. Reduce heat to low; cook 3 minutes or until cheese melts, stirring frequently.