Lay lahvosh on a work surface with longest sides parallel to surface edge and smooth, lighter sides up. Spread each with 1/2 cup pesto. On each sheet, place half of cheese slices on two-thirds of pesto, leaving 2 in. uncovered at top edge for sealing. Cover cheese with arugula. Starting with bottom edge, roll up each lahvosh and press to seal edge, securing with toothpicks if needed.
Slice each roll into 1-in. pieces, remove toothpicks if used, and arrange on a platter. Makes about 32 pieces.
*Substitute 4 flour tortillas (10 in. wide).
Note: Nutritional analysis is per appetizer serving.