HEAT oven to 375ºF. Pour dressing into blender. Add tomatoes and 1/2 the roasted peppers; pulse just until blended. Spread 1/4 cup onto bottom of 13x9-inch pan. Chop remaining roasted peppers.
FILL pasta shells with fish; place, filling-sides up, over sauce in pan. Cover with chopped peppers and 1/2 the cheese; top with dressing mixture, remaining cheese and pepper strips.
BAKE 35 min. or until fish flakes easily with fork and filling is heated through.