With the unofficial end of summer is practically upon us, it’s back to school for many – Rustic Kitchen softens the blow at their Cambridge location with a neighborhood prix fixe menu that even a student could afford. Chef Mark Usewicz’s four-course menu will be available from Sunday through Thursday after Labor Day and will feature seasonal selections like white corn soup with shell beans and calabrese sausage; squash blossom, taleggio and walnut risotto; and grilled lamb loin with swiss chard, currants and caponata. Call Rustic Kitchen at 617.354.7766 for more information or to make reservations.