Layer 8 filo sheets, one at a time and spray each sheet with vegetable spray. Cover the unused filo sheets with a damp kitchen towel or damp paper towel to keep the remaining filo from drying.
Spread artichoke and feta mixture along the long edge of the pastry,
Fold in edges before rolling, then roll filo in a jelly roll fashion and place on parchment lined cookie sheet, brush with melted butter.
Slice pastry, on a diagonal, 2/3 of the way through before baking; this will allow you to slice each piece using a serrated knife after the strudel is baked without shattering the filo dough.
Place in a pre-heated 375°F oven and bake for about 40 minutes or until the strudel has a nice even golden color.
Remove strudel from oven, allow to cool slightly, then cut the slices with a serrated knife.