Trim the ends of 3 large zucchinis and slice them into 1/8-inch ribbons. Sprinkle the zucchini with 1 teaspoon of sea salt and place them in a colander to allow them to sweat for about 15 minutes. Gently pat the zucchini dry with paper towels to remove excess moisture.

In a large skillet, heat 2 tablespoons of extra virgin olive oil over medium heat. Add 3 minced garlic cloves and sauté for about 1 minute until fragrant. Add 10 ounces of fresh baby spinach, cooking until wilted and any liquid evaporates, about 3-4 minutes. Remove from heat and set aside to cool slightly.

In a mixing bowl, whisk together 4 large eggs, 1/2 cup of whole milk, and half of the crumbled 8 ounces of feta cheese along with 1 bunch of chopped fresh dill until frothy and well combined.

Preheat your oven to 375°F (190°C). Grease a 9x13-inch ceramic baking dish. Layer one-third of the prepared zucchini ribbons evenly across the bottom of the dish, followed by the sautéed spinach mixture. Repeat until all ingredients are used up.

Carefully pour the egg mixture over the layers of zucchini and spinach, using a fork to gently poke into the layers, ensuring the mixture seeps throughout the casserole.

Scatter the remaining crumbled feta cheese unevenly over the top to create a blistered crust.

Place the baking dish in the preheated oven and bake for 35-40 minutes until golden-brown. If needed, turn on the broiler for an additional 2 minutes for a crispy finish.

Once out of the oven, let the casserole cool for about 10 minutes. Garnish with freshly grated lemon zest and additional sprigs of dill.