Asparagus and Red Onion Frittata

1 Tbsp olive oil
1/2 red onion, diced
1 small bundle asparagus, woody bases discarded, tops cut into 1" lengths
Salt and freshly ground black pepper
1 Tbsp chopped flat-leaf parsley (optional)
6 eggs
2 Tbsp water

Heat olive oil over medium-high heat in a medium-sized saute pan. Saute red onion until translucent and beginning to brown. Season to taste. Add asparagus; cook 2-3 minutes or until crisp-tender.

While asparagus is cooking, break eggs. Whisk together with water. Season with salt and pepper to taste.

Lower heat to medium. Sprinkle on parsley, then pour on egg mixture. Cook, stirring from the bottom with a heat-proof spatula, until about half done. Shake pan to distribute evenly, then pop the entire pan in a 400- to 450-degree oven (or under the broiler) for 3 to 5 minutes to cook the top.