Recipe

Drain Ricotta

1. Line sieve with a few layers of cheesecloth or paper towel. Scrape in ricotta. To remove excess moisture, let drain for 4 hours, or overnight, in refrigerator.

Prepare Filling

1. Heat 2 tablespoons of olive oil in large frying pan over medium heat. Add onion and sauté for 2 minutes, or until softened. Add ham and cook for another 5 minutes, or until lightly browned. Reduce heat to medium-low, then add squash and remaining 2 tablespoons of oil. Continue cooking for 15 minutes, or until squash is soft, lightly browned and quite dry. Mash with fork and season well with salt and pepper. Remove from heat and let cool.
2. In large mixing bowl, beat eggs. Add ricotta and squash mixture and stir until uniform. Add Parmesan and mozzarella and stir until just combined. Season with salt and pepper, to taste.

Make Tart

1. Preheat oven to 375°F. While oven is heating, grease tart pan with butter.
2. Working with 1 phyllo sheet at a time (and keeping the rest covered with damp towel), place sheet into tart pan with excess hanging off to one side. Brush surface lightly with melted butter. Lay 9 remaining sheets into pan in slightly different overlapping positions, brushing each with butter, so that ends overhang pan on all sides to form circle.
3. Scrape filling evenly into crust. Working with 1 phyllo sheet at a time, fold edge of sheet over filling to enclose and brush with butter. Repeat with remaining phyllo sheets. Use sharp knife to cut 8 slits on top of pastry.
4. Place tart pan on baking sheet and bake for 1 hour in center of oven, until tart is puffed in middle and pastry is golden. If phyllo is getting too brown, cover loosely with foil for
   last 10 minutes. Serve warm or at room temperature.