Squeezing the zucchini is the single most important step -- do not skip or rush it. Fresh dill is essential; dried dill is not a substitute. Use block feta packed in brine, crumbled by hand. Score the top phyllo before baking to release steam and enable clean cuts. Rest 15 minutes before cutting. The assembled pie can be frozen unbaked for up to 2 months; bake from frozen at 180C/350F for 60 to 70 minutes.