Preheat oven to 375 degrees F.

 

Brush 15 x 10 x 1" baking sheet with butter. Place 1 phyllo sheet in prepared pan (edges of phyllo may go up sides of baking sheet). Brush phyllo with butter, sprinkle with 1 Tbsp Parmesan cheese.

 

Repeat layering with remaining phyllo, butter and Parmesan cheese. Top with even layers of mozzarella cheese and onion, then tomatoes. Sprinkle with oregano and thyme.

 

Bake until crust is crisp and golden brown at edges, cheese melts and tomatoes are tender, about 30 minutes. Let stand 5 minutes.