Dip the frise or dried bread into a bowl of water (or into salt water that you trust) and let soften for about 15 seconds. They should be soft enough not to crunch but not so soft that they crumble when you pick them up. Set the rusks on a plate, two per person. Cut some tomatoes in half and rub the cut side into the frisa halves, using the bread as though it were a grater. Top with a handful of arugula.
Drizzle oil over everything until the frise are pregnant with it and deeply perfumed. Salt to taste.
Eat the frise with your hands, picking them up like you would a bruschetta. Have a large napkin nearby: If you can eat these without trickle of thick, green, fragrant oil happily running down your chin—and possibly arm—you're doing it wrong.
Serve with a rosato from the Salento.