Bring water to a boil for the pasta. In a serving mixing bowl combine the tomatoes, scallions and mozzarella and set aside. Add fresh pasta to water and cook quickly just until al dente; drain and place in serving bowl. In a medium size skillet melt butter with olive oil. Add watercress and arugula and saute for a couple of minutes just to wilt. Add yellow bell pepper and saute a minute just to begin cooking and remove from heat. Add arugula mixture and toss the ingredients together with salt and pepper red flakes. Transfer to a bowl and sprinkle fresh radish and cucumbers on top.