For best flavor, select slender, young asparagus that's as fresh as possible. For a more substantial frittata, use three eggs instead of two, and an additional tablespoon of milk. And you can certainly double the recipe to make two frittatas or one larger one that you can cut to serve two or three people.
1 Tbs olive oil OR butter OR bacon fat for frying
3 small new potatoes, unpeeled & chopped
1/4 cup chopped onion
3/4 cup to 1 cup asparagus, chopped into 1" pieces
Salt & pepper to taste
2 Tbs milk
Heat the oil (or melt the fat or butter) in a medium skillet or frying pan (mine is 10") over medium-high heat. Add potatoes and saute until softened and light golden brown. Add onions & saute until softened & translucent. While the onions are cooking, whisk together the eggs and milk in a small bowl, then stir in the oregano or other herb, and set aside. Add asparagus to the skillet and saute until it starts to soften & turn deep green, about 1 to 2 minutes max. Pour in the egg mixture, reduce heat to low, partially cover and cook until just set, and then flip over (see note) to cook the other side for 1 to 2 minutes. Serve hot.
Note: For easy flipping, cover the skillet with a plate that's a little larger than the frittata, hold in place with one hand and carefully lift the skillet by the handle with your other hand, and in one motion turn turn the skillet over so that the frittata falls onto the plate. Then gently slide the frittata back into the skillet, uncooked side down, to finish cooking. Use the same technique to remove the fully-cooked frittata from the skillet when ready to serve.