Preheat oven to 425°. In a small bowl, combine biscuit mix, water and oregano to form a soft dough. Press dough to fit a greased 12-in. pizza pan; pinch edge to form a rim. Bake 10-12 minutes or until lightly browned.
Brush 1/4 cup vinaigrette over crust; top with olives, red pepper and cheeses. Bake 8-10 minutes or until cheese is melted and crust is lightly browned.
Sprinkle with cucumber and tomato before serving. If desired, drizzle with additional vinaigrette.