Place bell pepper halves, cut sides down, on an aluminum foil-lined baking sheet.
Broil 5 inches from heat (with electric oven door partially open) 8 to 10 minutes or until bell peppers look blistered.
Place bell peppers in a heavy-duty zip-top plastic bag; seal and let stand 10 minutes to loosen skins. Peel peppers; remove and discard seeds. Pat dry with paper towels.
Beat cheeses at medium speed with an electric mixer until smooth.
Spread half of cheese mixture in a plastic wrap-lined 8- x 4-inch loafpan. Top with 4 pepper halves. Spread remaining cheese mixture over peppers; top with remaining pepper halves. Chill 8 hours.
Unmold onto a serving dish, and drizzle with Tomato-Basil Vinaigrette. Serve on mixed greens.