Saute the onions in the olive oil over medium heat until tender and golden. Remove skillet from heat.
Place tofu in a mixing bowl and crumble with a fork.
Add dill, lemon juice, salt and pepper, onions, and spinach.
Stir thoroughly to combine.
Preheat oven to 350°F.
Remove half of the phyllo dough from the package and cover the rest with plastic wrap and/or a damp towel to prevent it from drying out.
Brush the bottom and sides of a 13" X 9" glass baking dish with the melted margarine. Place 2 phyllo sheets in the dish and press in lightly.
Lightly brush with margarine (make sure to get the edges) and top with 2 more sheets and continue repeating until you have used half of the package of phyllo dough.
Spread the spinach mixture in dish on top of the phyllo dough.
Top with remaining phyllo dough in the same way as before, tucking or rolling in the excess edges when finished.
Bake 45 minutes until golden and filling is hot.
Let stand 10 minutes before serving.
