Step 1Heat the oven to 350 degrees.
Step 2In a large bowl, whisk together the egg yolks and condensed milk until combined. Mix in the lime juice and zest until thoroughly combined. This makes a scant 3 cups of filling.
Step 3Pour the filling into the prepared pie shell and place the pie in the oven. Bake just until the filling is set and jiggles only slightly when tapped, 10 to 15 minutes. Remove from the heat and cool on a rack, then refrigerate the pie, uncovered, until completely set, preferably overnight.
Step 4Top as desired and serve.