Preheat oven to 400 and remove phyllo dough from freezer to thaw.
Thinly slice shallots and add to a skillet with 1 tbsp butter, a pinch of salt and pepper. Cook stirring often on medium to low heat for about 20 min or until the shallots are cooked down and a deep brown.
Add all filling ingredients to a bowl and mix to combine.
Melt butter and lay out one sheet of phyllo dough. Brush with melted butter and then top with another sheet of phyllo dough. Repeat with all six sheets, brushing butter between each layer.
Using a veggie peeler, slice the zucchinis into ribbons.
Add filling to the middle and then add zucchini ribbons overtop however you want to place them. I did layers and then rolled additional ribbons into little spirals like flowers. If you are adding leek, sprinkle the slices over top.
Crinkle the phyllo dough in on each side to create the crust. If the dough is flaking, add a little melted butter to those edges. Brush the top with more butter.
Bake for about 30 min or until nicely golden brown. Drizzle the top with balsamic glaze and serve. Enjoy!