Arrange the oven rack to the center position and preheat the oven to 375°F (190°C). Grease a 9-inch or 8×10-inch baking pan thoroughly with non-stick cooking spray. Line the pan with parchment paper cut to fit with edges slightly overhanging for easy removal.

Bring a large saucepan of water to a boil. Salt the boiling water generously. Add the asparagus and cook for 1-2 minutes until bright green and tender-crisp. Immediately transfer the asparagus to an ice water bath to stop cooking. Drain, pat dry, and set aside.

In a large bowl, combine eggs, 2 tablespoons of ricotta, whole milk, parmesan, chives, dill, and Dijon mustard. Season with ½ teaspoon kosher salt and ¼ teaspoon black pepper. Whisk vigorously until the mixture is smooth and well blended. Set aside.

Arrange half of the asparagus in a single row inside the prepared baking pan. Pour the egg custard over the asparagus evenly. Lay the remaining asparagus spears on top in a single row. Dot with the remaining ricotta and lightly season with additional salt and pepper.

Place the pan in the preheated oven and bake for 28 to 38 minutes, until the frittata has risen and is just set with no jiggle in the center. Remove from the oven and allow to cool in the pan on a wire rack for 5 minutes.

Use the parchment paper edges to carefully lift the frittata out of the pan. If it sticks, gently run a butter knife around the edges to loosen it. Transfer to a serving platter and slice between asparagus rows. Garnish with additional fresh herbs, parmesan, and optional prosciutto or smoked salmon if desired. Serve warm or at room temperature.