Zucchini slab frittata recipe

Ingredients

• Neutral oil, such as grapeseed or sunflower
• 2 pounds zucchini, sliced into paper-thin rounds with a mandoline, food processor, or sharp knife
• 2 teaspoons kosher salt
• 1 medium onion (8 ounces), sliced paper thin with a mandoline, food processor, or sharp knife
• ½ cup mixed fresh herbs, such as basil, rosemary, parsley, or thyme, roughly chopped
• ½ cup whole-milk ricotta cheese
• 6 large eggs
• 4 ounces cream cheese
• 1¼ cups milk
• Freshly ground black pepper

1. Preheat the oven to 350°F. Grease a 9 × 9- or 10 × 10-inch square baking pan with oil.
2. Put the zucchini in a colander and sprinkle with 1 teaspoon of the salt. Gently toss the two together and let sit for 10 minutes to release a bit of liquid.
3. Heat 1 tablespoon oil in a large skillet set over medium-high heat. Add the onion and cook, stirring frequently, until soft and translucent, 2 to 3 minutes. Transfer the onion to the prepared baking pan, leaving the skillet on the heat. Add another splash of oil to the skillet. Add half the zucchini to the skillet, giving it a gentle squeeze to remove as much liquid as possible before you put it into the pan. Cook, stirring frequently, until the zucchini slices shrink and start to color, 4 to 5 minutes. Transfer to the baking pan with the onion. Add the second half of the zucchini to the skillet, again giving it a squeeze, adding a bit more oil if the pan seems dry. Add half the herbs and cook, stirring frequently, until the zucchini turns golden, 3 to 4 minutes. Add the herbed zucchini to the baking pan.
4. Combine the ricotta with the remaining herbs and ½ teaspoon salt.
5. Combine the eggs, cream cheese, the remaining ½ teaspoon of salt, the milk, and several grinds of pepper in a blender. Blend until smooth. Pour the custard mixture over the vegetables, then use a tablespoon to dot the top with the herbed ricotta.
6. Bake until the top of the frittata is golden and the center doesn’t weep when pricked with a toothpick, 45 to 50 minutes. Allow to cool for at least 20 minutes before serving.