Preheat your oven to 350°F. While it heats, finely dice the shallots into 1/4-inch pieces and slice the asparagus into 1-inch lengths, removing and discarding the tough woody ends. Having everything prepped and ready before you start cooking ensures smooth transitions between steps and allows you to focus on building flavor through proper cooking.

Heat 1 tablespoon of olive oil in a 10-inch nonstick skillet over medium heat. Add the diced shallots and cook for 2-3 minutes, stirring occasionally, until they become translucent and fragrant—this develops their natural sweetness. Add the remaining 2 tablespoons of oil along with the sliced asparagus and a pinch of salt, then cook for 2 minutes. Pour in the water and continue cooking for 2-3 minutes more until the asparagus is just tender-crisp. I like to taste a piece at this point to ensure it has a slight firmness—the residual heat during baking will continue to soften it.

In a medium bowl, whisk together the whole eggs and egg whites until well combined. Add the cottage cheese, 1/4 teaspoon salt, pepper, and dried dill, then stir gently until the mixture is evenly blended—avoid overbeating, as you want to maintain some texture from the cottage cheese rather than completely homogenizing it. The cottage cheese will add creaminess and protein while the dill provides herbal seasoning that complements the asparagus beautifully.

Pour the egg and cottage cheese mixture from Step 3 over the sautéed asparagus and shallots in the skillet, stirring gently to distribute the vegetables evenly. Cook over medium heat for 3-4 minutes without stirring, until the edges begin to set and pull away slightly from the sides of the pan. This initial stovetop cooking helps the frittata firm up before it goes into the oven, creating a better texture in the final dish.

Scatter the crumbled feta cheese evenly over the surface of the partially set frittata. Transfer the skillet to the preheated 350°F oven and bake for 15-17 minutes, until the top is lightly golden and the center is just set when gently jiggled. I find that checking at the 15-minute mark helps prevent overcooking—the frittata should jiggle just slightly in the very center but be mostly firm.

Remove the skillet from the oven and let the frittata cool for 3-5 minutes before slicing. This resting time allows the structure to set completely and makes serving easier. Slice into wedges directly from the skillet and serve warm or at room temperature.