Add onion and cook, stirring occasionally, until starting to brown, about 10 minutes.
Add water and reduce heat to medium-low.
Cover and cook, stirring occasionally, until very tender and brown, about 15 minutes more.
Set aside to cool for 5 minutes.
Meanwhile, preheat oven to 350 degrees F. Generously coat 24 (1/2-cup) muffin cups with cooking spray.
(Alternatively, line muffin cups with parchment-paper liners.)
Whisk eggs in a very large bowl.
In batches, finely chop greens in a food processor.
Mix into the egg mixture to combine.
Divide the mixture among the prepared muffin cups (they will be full).
Bake until set, 25 to 30 minutes.
Let cool in the pans for 5 minutes.
Loosen the edges with a knife and turn out onto a clean cutting board.
Serve warm or at room temperature.
Let cool completely before refrigerating for up to 3 days or freezing for up to 3 months.
- Daily Values (DVs) are the recommended amounts of nutrients to consume each day.
(-) Information is not currently available for this nutrient.
