Preheat your oven to 375°F (190°C) and prepare your baking sheet.
Wash and dry the spinach, then chop it finely.
In a mixing bowl, combine the chopped spinach, crumbled feta, chopped green onions, dill, beaten egg, salt, and pepper.
Unroll the phyllo dough and cover it with a damp towel to prevent drying.
Take one sheet of phyllo dough, brush it lightly with olive oil, and fold it in half lengthwise.
Spoon a generous amount of filling along one edge of the folded dough.
Fold the dough over the filling to form a triangle and continue folding until you reach the end.
Place the completed triangles on the prepared baking sheet and brush the tops with more olive oil.
Bake in the preheated oven for 25-30 minutes or until golden brown.
Allow to cool slightly before serving.