On large cookie sheet, unroll crescent rolls and press seams together. Bake at 350 degrees for 8 to 10 minutes. Cool completely.
Blend dressing, mayonnaise, and cream cheese until smooth. Spread evenly over baked rolls. Mix vegetables together and sprinkle over cream cheese mixture. Sprinkle the grated cheddar cheese evenly on top. Press lightly with hands. Refrigerate at least 2 hours before serving.
Cut into squares. Makes 30 squares.