Whisk together first 5 ingredients in a bowl until smooth; dip tomato slices evenly in batter.
Pour oil to a depth of 2 inches into a large heavy skillet. Fry tomato slices, in batches, in hot oil over medium-high heat 4 minutes on each side or until slices are golden.
Arrange lettuce evenly on 6 plates; top each with 2 tomato slices. Sprinkle evenly with walnuts; drizzle with Rose Vinaigrette. Garnish, if desired.
* For extra-crispy fried tomatoes, dip in batter twice.