1. Adjust oven rack to upper-middle position and heat oven to 350 degrees.
2. Heat oil or butter in 10-inch nonstick skillet over medium heat. Swirl skillet to distribute evenly over bottom and sides. Add shallot; sauté until softened, 3 to 4 minutes. Add mint, parsley, and asparagus; toss to coat with oil. Spread in single layer.
3. Meanwhile, stir 3 tablespoons of the cheese, salt, and pepper into eggs.
4. Pour mixture into skillet; stir lightly with fork until eggs start to set, (illustration 1 below). Once bottom is firm, use thin, nonmetallic spatula to lift frittata edge closest to you. Tilt skillet slightly toward you so that uncooked egg runs underneath, (illustration 2). Return skillet to level position and swirl gently to evenly distribute egg. Continue cooking about 40 seconds, then lift edge again, repeating process until egg on top is no longer runny.
5. Transfer skillet to oven; bake until frittata top is set and dry to touch, 2 to 4 minutes, making sure to remove frittata as soon as top is just set.
6. Run spatula around skillet edge to loosen frittata; invert onto serving plate. Serve warm, at room temperature, or chilled.
STEP BY STEP: Setting Eggs for a Frittata
1. Pour the egg mixture into the nonstick skillet and stir lightly with a fork until it starts to set.
2. Once the bottom of the eggs is firm, use a thin, nonmetallic spatula to push the frittata back so the uncooked egg runs underneath.