Thaw the 2 package frozen chopped spinach thawed completely completely, then transfer it in batches to a clean Kitchen Shears towel or several layers of cheesecloth. Wring it out as firmly as you can — you want it as dry as possible. This is the single most important step: excess moisture will make your pie soggy. Set aside.

Heat the 3 tbsp olive oil in a Skillet over medium heat. Add the diced 1 yellow onion finely diced and cook, stirring occasionally, until softened and translucent, about 5–6 minutes. Add the 4 cloves garlic minced and cook for 1 more minute until fragrant. Remove from heat and let cool slightly.

Crack 2–3 large eggs per serving into a Mixing Bowl. Add a pinch of salt and a few grinds of black pepper. Whisk until fully combined — no white streaks. Optional: add 1–2 tbsp milk (richer) or water (lighter) per serving. Use a nonstick or well-seasoned carbon steel pan. Have a Rubber Spatula or Wooden Spoon ready before the pan goes on heat.

Add ½ tbsp unsalted butter to a Skillet. For creamy curds, use medium-low or low heat. For firmer eggs in less time, use medium — no higher. Once butter melts and coats the pan, pour in your whisked eggs. Let sit undisturbed 20–30 seconds until edges just begin to set. Using a Spatula, pull eggs in slow, sweeping strokes — lift and fold rather than stir constantly. This builds larger, softer curds. More frequent stirring gives smaller, more uniform curds. Total cook time: 3–6 minutes. Low heat = 5–6 min, creamiest result. Medium heat = 3–4 min, slightly firmer. Remove when almost no liquid egg remains but the surface still looks slightly wet and shiny.

Crack 2–3 large eggs per serving into a Mixing Bowl. Add a pinch of salt and a few grinds of black pepper. Whisk until fully combined — no white streaks. Optional: add 1–2 tbsp milk (richer) or water (lighter) per serving. Use a nonstick or well-seasoned carbon steel pan. Have a Rubber Spatula or Wooden Spoon ready before the pan goes on heat.

Add ½ tbsp unsalted butter to a Skillet. For creamy curds, use medium-low or low heat. For firmer eggs in less time, use medium — no higher. Once butter melts and coats the pan, pour in your whisked eggs. Let sit undisturbed 20–30 seconds until edges just begin to set. Using a Spatula, pull eggs in slow, sweeping strokes — lift and fold rather than stir constantly. This builds larger, softer curds. More frequent stirring gives smaller, more uniform curds. Total cook time: 3–6 minutes. Low heat = 5–6 min, creamiest result. Medium heat = 3–4 min, slightly firmer. Remove when almost no liquid egg remains but the surface still looks slightly wet and shiny.

Lay one sheet of 1 package phyllo dough thawed overnight in the refrigerator, #4 thickness (standard) into the buttered Baking Dish, letting any excess drape over the sides. Brush it all over with melted ¾ cup unsalted butter melted (about 1.5 sticks), or use olive oil. Repeat with 7 more sheets (8 total), brushing each one with ¾ cup unsalted butter melted (about 1.5 sticks), or use olive oil before adding the next. This forms your bottom crust.

Spread the 2 package frozen chopped spinach thawed completely and 16 oz feta cheese crumbled (block feta preferred over pre-crumbled) filling evenly over the 1 package phyllo dough thawed overnight in the refrigerator, #4 thickness (standard) base, smoothing it into the corners with a Spatula.

Layer 8 more sheets of 1 package phyllo dough thawed overnight in the Refrigerator, #4 thickness (standard) on top of the filling, again brushing each sheet generously with ¾ cup unsalted butter melted (about 1.5 sticks), or use olive oil. For the final top sheet, tuck any overhanging edges down and inward along the sides of the dish to create a neat border, and brush the top thoroughly with ¾ cup unsalted butter melted (about 1.5 sticks), or use olive oil.

Using a very sharp Knife, score the top layers of 1 package phyllo dough thawed overnight in the refrigerator, #4 thickness (standard) (don't cut all the way through) into the portion sizes you want — typically 8 to 12 squares or rectangles. This prevents the top from shattering uncontrollably when you cut it after baking. Sprinkle a few drops of water on top to help prevent the edges from curling.