Preheat oven to 375. Unroll both packages of crescent rolls and lay in the bottom of a 9 x 13 baking pan lining the bottom, squeeze it all in..you may have some left over. Bake 10-12 minutes...or until light golden brown; remove from oven.
Meanwhile combine mayonnaise, sour cream and soup mix; mix well. Drain spinach in small colander, squeezing out as much moisture as possible; add to mixture. Drain artichokes and water chestnuts..chop with knife or food chopper. Add artichokes, water chestnuts, feta cheese and garlic..mix well with all the other ingredients.
Spread spinach mixture evenly over crust. Sprinkle Parmesan cheese over entire pan. Bake 10-12 minutes or until heated through. Remove from oven; cut into squares.