• Thaw the phyllo dough in the fridge overnight. Just before making the filling, set the phyllo dough on the kitchen counter (still in its packaging) to bring to room temperature.

Make the Filling

• In a small saute pan, add the oil and heat until shimmering. Add the onions and saute on medium low heat for about 5-6 minutes or until translucent. Add the garlic and stir until fragrant, about 30 seconds.
• Meanwhile, in a medium mixing bowl, crack the egg and whisk. To this bowl, add the onions and garlic.
• To the egg/onion mixture, add the spinach, salt, pepper, pepper flake, nutmeg, Parmesan and feta cheese and lemon juice. Stir until all the ingredients are evenly distributed. Set aside.

To Assemble

• Arrange oven rack in the center of the oven. Preheat the oven to 375 degrees Fahrenheit (190 Celsius). Line a sheet pan with parchment paper. Set aside.
• Melt the butter, or use olive oil, add a pinch of salt and stir. Set aside.

  Unroll the phyllo dough. Transfer three sheets to a clean work surface. Immediately, cover the remaining phyllo with a sheet of parchment or plastic wrap and a moist tea towel.

  Working quickly, arrange the stack of three phyllo sheets portrait wise (with the shortest side towards you). Use the straight edge of a ruler to guide your cut. Using a pizza wheel or pairing knife, cut the phyllo into three equal strips for small 3 inch triangles or two equal strips for large 4 1/2 inch triangles. Hold the top of each strip down while using a pastry brush to throughly "paint" the phyllo with butter or olive oil (you only need to brush the top of the three sheets/strips before adding the filling and folding).
• Spoon or scoop the filling onto the strips at one end. For small triangles, use about 2 teaspoons of filling. For large triangles use about 1 1/2 tablespoons of filling.

  Fold the phyllo into a triangle, nudging the filling back in if needed. Don't worry if there's a bit of squeeze out. It'll eventually get folded in. Continue to follow the triangle fold all the way to the end of the strip, lightly brush with butter or oil after two to three folds. Once you get to the end, if there's a "tail" left, trim it off, lightly brush the top with butter/oil, then transfer to the pan, butter/oil side down, then brush the back.

  Repeat until all the filling is used.
• Arrange on the sheet pan and bake the parcels for about 30-35 minutes or until golden brown and crisp.

Make the Yogurt Dip

• In a medium bowl, stir the yogurt, lemon zest and juice, chives and dill and sea salt. Chill until ready to dip.

To Share

• Share warm or at room temperature with the yogurt dip. See blog post for pairing ideas.

To Store

• Allow the triangles to cool completely. Store in a covered container in the fridge for up to three days. Freeze parcels on a sheet pan in the freezer, then transfer to a storage container for up to one week. Thaw in the fridge or at room temperature. To rewarm, place in a 350 degrees Fahrenheit (180 Celsius) oven for about 10-15 minutes (keep an eye on them so they don't get too dark).