Step #3 From a narrow side, cut filo stack into 3 equal strips.
Step #4 Lift 1 strip from stack & lay flat; cover remaining pieces with plastic wrap to prevent drying.
Step #5 Mist the single strip lightly with cooking oil spray.
Step #6 Place 1 tbsp of the cheese mixture on one end of strip.
Step #7 Bring a corner end of filo strip over filling to meet opposite edge of filo, forming a triangle, then continue to fold as a triangle (like a flag) until the whole strip is wrapped around filling.
Step #8 As shaped, keep filled triangles covered with plastic wrap.
Step #9 Repeat to use remaining cheese & filo.
Step #10 Place triangles, loose ends beneath, well apart on a nonstick baking sheet.
Step #11 Mist triangles lightly with cooking oil spray.
Step #12 If making ahead, freeze solid, then package airtight.
Step #13 Bake in a 375° oven until golden, 12 to 14 mins (20 mins, if frozen).