Saute vegetables in olive oil until cooked. Add soy sauce and ginger and let cool. Preheat oven to 400 degrees. Fold a sheet of phyllo in half, lengthwise, add some of vegetables, and roll up like an eggroll, turning a half-inch of the edges inward as you roll. Brush with butter and place on baking sheet. Repeat to use all ingredients. Bake about 15 minutes, then turn rolls over and bake for another 15 minutes. Serve hot.