Lightly pound out each chicken breast with meat mallet. Set aside. Saute green onions and garlic in the teaspoon of butter until onions are tender. Add drained spinach, dill, salt and pepper. Cook until mixture is thoroughly heated. Add crumbled feta cheese. Divide into four equal parts. Place this mixture in the center of each chicken breast and roll up. Place on greased pan and bake at 180ºC or 20 minutes. Butter each sheet of filo on one side with melted butter; place on top of each other, making four stacks, each four sheets high. Place each cooked and stuffed chicken breast in the middle of the lower end of one stack. Fold over sides and roll up. Brush with melted butter. Place on greased pan and bake at 375 degrees until golden brown.