In a medium bowl, mix together all the ingredients for the tart (except for the puff pastry). Set Aside.
Roll your puff pastry sheet into an approximately 1⁄4“ thick 20 x 20 cm square (or whatever shape you prefer).
Place your pastry on a baking sheet lined with parchment paper and prick all over using a fork.
Bake for approximately 15 minutes or until lightly golden (the pastry will finish cooking at a later stage).
While the pastry is baking, cut your vegetables into small and thin pieces so that they bake evenly (for larger vegetables such as butternut, we recommend blanching for 1-2 minutes before seasoning).
Season the vegetables with a drizzle of olive oil, salt, and sumac.
Top the lightly golden puff pastry with the cheese mix, and then arrange the vegetables on top.
Bake for approximately 20 minutes or until golden.
