In a medium saute pan, add olive oil to coat and heat until hot. Add in onion, fennel, and garlic. Season with salt and pepper and cook until very soft and starting to caramelize. Set aside to cool completely.
While onions cool, blanch the spinach. Bring a large pot of water to a boil and season with salt. Once boiling, blanch spinach for 30 seconds, then transfer directly to an ice bath.
Once cold, squeeze all the liquid out of the spinach. Squeeze, squeeze, squeeze! You want to get as much of the water out as you can!
Roughly chop the drained spinach and add to a large bowl. When the onion mixture is fully cooled, add to the bowl with the spinach. Add in ricotta, parmesan, 2 eggs, nutmeg, and lemon zest. Mix until combined. Season with salt and pepper to taste.
Preheat the oven to 425F.
On a floured surface, roll puff pastry to about an 11x11” square. It doesn’t have to be precise! Slightly trim the corners of the pastry to round the edges a bit *
Transfer to a parchment lined sheet tray and add half of the spinach mixture to the center of the pastry leaving about a 3” border. Cover spinach with sliced hard boiled eggs and top with remaining spinach mixture to cover.
Fold and crease the dough up over the filling to create the crust. Egg wash crust and sprinkle with sesame seeds.
Bake for 25-35 minutes, until pastry is golden and puffed.
Drizzle with EVOO and garnish with fennel fronds, if desired.
Video
Notes
*Don’t worry too much about the pastry being perfectly round or the exact dimensions. Some store bought puff pastry sheets are slightly larger than others (dufour is a bit larger than pepperidge farm), but both still work! It’s meant to look rustic 🙂