4 slices bacon
3 eggs
1 teaspoon water
cooking spray
1 tablespoon butter
1/2 white onion, diced

Preheat oven to 375.
Arrange bacon on a baking sheet.
Bake in the preheated oven until just crisped, 10 to 12 minutes.
Beat eggs and water together in a bowl.
Let the bacon cool on paper towels, about 5 minutes and break into small pieces.
Spray a 10-inch non-stick skillet with cooking spray.
Melt butter over medium heat until foaming, about 2 minutes.
Add onion once butter is no longer foaming.
Cook and stir until tender but not browned, 4 to 5 minutes.
Increase heat to medium-high. Pour eggs into the skillet and cook until mostly set, about 2 minutes.
Lift the omelet with a spatula as the center rises; tilt the skillet so that uncooked eggs run to the center of the pan.
Cook until set, 2 to 4 minutes. Sprinkle bacon pieces onto the omelet and fold in half using the spatula.