Preheat your oven to 375°F (190°C). This is crucial for achieving that perfect frittata texture. Meanwhile, gather and prep all your ingredients. Chop the scallions, mince the garlic, and wash the spinach. This will speed up the cooking process.

In a large, oven-safe skillet, heat the vegetable oil over medium heat. Add the sliced scallions and minced garlic, sauté until fragrant. It generally takes about 2–3 minutes. Watch it closely; we don’t want burnt garlic ruining our frittata!

Next, toss in the baby spinach. Stir it around until wilted, which takes about another minute or so. The spinach will reduce in size drastically, releasing moisture that adds flavor.

In a separate bowl, whisk together the eggs, whole milk, kosher salt, and black pepper until well combined and slightly frothy. This is where the magic starts. The frothiness will contribute to the frittata rising beautifully.

Pour the egg mixture directly into the skillet with the sautéed veggies. Gently stir to combine everything evenly. At this point, sprinkle in the crumbled feta cheese, dried oregano, and chili flakes if you’re using them.

Allow the frittata to cook on the stovetop for about 5 minutes. You want the edges to start setting but the center to remain somewhat runny. This step is essential for that perfect texture.

Once the edges are set, carefully transfer the skillet to the preheated oven. Bake for about 15–20 minutes, or until the frittata is golden brown on top and fully set in the center. Use a toothpick to check; it should come out clean from the center.

Once done, remove the skillet from the oven. Allow it to cool slightly. As it cools, prepare your garnish by mixing diced tomato, diced red onion, lemon juice, olive oil, and seasonings. This fresh topping will elevate the flavors.