• NOTE: You can cook the frittata on the stove or in the oven. If you cook it on the stove, you must use a nonstick pan. If you have a flippable frittata pan, use it. Otherwise, you'll need to flip the frittata using two round platters or round pizza pans to invert it. The stove method is tastier but the oven method is easier. You need an oven-safe skillet for the baking method. See the Notes section if you'll be using the oven.
• Rinse the asparagus and pat dry. Trim off and discard the tough ends (remove the bottom 2 inches or so.) Cut each remaining stalk into three equal pieces.
• Pre-cook the asparagus until it's crisp-tender (you'll finish it by sautéeing it afterward). Add the asparagus to an empty 10-inch or 12-inch nonstick skillet. (If you'll be baking the frittata later, make sure to use an oven-safe pan.) Add just enough water to cover the vegetables. Cover the pan and place it over high heat to boil. When the water is boiling, cook the asparagus for about 7 minutes if it's thin, or a couple minutes longer if it's thicker. When it's crisp-tender, drain the asparagus in a colander in the sink and wipe out the pan with paper towels to dry it.
• While the asparagus is cooking, beat the eggs with a fork or whisk in a small mixing bowl and add the black pepper, whisking it in. Press the garlic (if you have a garlic press) or peel and chop it finely with a knife. Grate the cheeses (I cut mine into chunks and whirl them in the blender.) If you'll be cooking the frittata on the stove, set out two spare round pans or platters that will be used later for inverting the frittata.
• Heat 1 tablespoon of olive oil in the dry skillet over medium-high heat and add the garlic, stirring it around. After about 30 seconds, add the asparagus back to the pan and stir it to coat it with olive oil. Let the asparagus finish cooking until you can easily insert a fork in it, stirring occasionally to make sure the garlic doesn't burn, and lowering the heat if necessary. It should take about three minutes for thin asparagus and a few minutes longer for thicker ones.
• Turn off the heat and use a slotted spoon to transfer the asparagus to a medium mixing bowl. Pat the asparagus with a paper towel if there is excess liquid. Stir in the Parmesan and Romano.
• Add 4 teaspoons of olive oil to the skillet over medium heat. Spread the oil around and add the asparagus mixture, distributing it in an even layer. Pour the beaten eggs on top. If you'll be baking the frittata, follow the baking directions in the Notes section.

Stovetop Instructions

• Cook the frittata, covered, over medium heat on the stove until you see that the edges are browning and firm, and the bottom smells like it's done. The top should be almost set. (This could take at least 25 minutes.) If you used a frittata pan, flip it over to cook the second side.
• If you're using a regular nonstick skillet, when you are ready to cook the other side, turn off the heat. Wearing oven gloves, place one of your spare round pans or platters face down over the pan, and over the sink, invert the frittata onto the pan. The cooked side will be up. Then use your second spare pan or platter to invert the frittata again, so that the raw side is up. Finally, invert the frittata back into your skillet.
• Finish cooking the frittata over medium heat, for about 6 minutes or until the bottom is firm and set. (You can gently lift the edge with a spatula to check it.) Slide the finished frittata onto a round platter and let it rest for a few minutes before slicing it.
• The frittata is delicious at room temperature but needs to be refrigerated within two hours. Store leftovers in the refrigerator for up to four days.