In medium bow, whisk together the eggs and milk. Stir in scallions, thyme, parsley, pepper and salt.
Place asparagus and water in large microwaveable bowl. Cover with vented plastic wrap and microwave on high power for 4 minutes, or until crisp-tender. Stop and stire after 2 minutes. Drain, pat dry, and add to egg mixture.
Heat medium nonstick skillet coated wtih cooking spray over medium heat. Pour one-quarter of egg mixture into skillet, allowing it to cover the bottom of the pan. Cook for 2-3 minutes, or until bottom just begins to set. Sprinkle with 1 tsp of cheese. Add one-quarter of asparagus pieces. Cook for 5 minutes, or until eggs are almost set.
Using a large spatula, fold the omelet in half. Cook for 3 minutes or until omelet is golden and cheese is melted. Turn onto a plate and keep warm.
Coat skillet with cooking spray and repeat process with remaining ingredients to make 3 more omelets. Garnish with chives.