INGREDIENTS
Cooking spray
1 tbsp
olive oil
1/4 cup
diced onion
1 cup
baby spinach leaves, coarsely chopped
2 oz
shredded part-skim mozzarella cheese (about 1/2 cup)
1/4 cup
2% reduced-fat milk
1/2 tsp
kosher salt
1/4 tsp
freshly ground black pepper
4
large eggs