Spring Veggie Frittata

First, preheat your oven to a medium-high temperature of 350 degrees Fahrenheit (or 175 degrees Celsius).

Next, heat a generous amount of olive oil in a substantial 10-inch skillet over a moderate flame. Gently sauté sliced leeks in the hot oil, sprinkling a small amount of salt over them, stirring occasionally until they become tender and start to lose their vibrant color, taking around 5 to 6 minutes. Add diced zucchini and sliced jalapeño; season with another pinch of salt. Continue to cook until the zucchini begins to soften and turn pale green, approximately 5 minutes. Add fresh asparagus spears; cook until they reach a bright green hue, roughly 1 minute. Add a handful of spinach leaves and yet another pinch of salt; cook until wilted, about 1 minute. Stir in cooked potatoes and let them heat through, taking around 5 minutes.

In a separate bowl, crack eggs into it; add a small amount of salt, black pepper, and cayenne. Whisk the mixture until it's well combined, taking at least 30 seconds to achieve this. Pour the egg mixture over the vegetables in the skillet, cooking it over a moderate flame. Add 3 ounces of crumbled feta cheese; stir gently until the cheese is evenly distributed throughout. Top with the remaining 1 ounce of feta cheese. Remove from heat.

Place the skillet in a preheated oven and let it bake until the eggs are set, taking 12 to 15 minutes. When nearly set, turn on your oven's broiler and cook until the top browns, 1 to 2 minutes. Remove from the oven and let it cool slightly; serve warm.