Work Week Lunch

1 Preheat your oven to 375 F.
2 Prepare 6 wells of a muffin tin with A LOT of cooking spray. Be generous! Eggs tend to stick. Muffin liners are a good alternative to avoid egg sticking to your pan.
3 Cook the spinach: Heat up a skillet over a medium flame and add the spinach. No need to add oil. Add salt and pepper. Cook the spinach, stirring occasionally until it has defrosted and the water has cooked out - about 10 minutes on medium-low heat. The pan should look pretty dry. We don't want soggy eggs! 
4 Meanwhile, whisk the eggs in a bowl. Add the milk and salt and pepper to taste (be generous). If using, add cheese. When the spinach is done, add the spinach to the bowl. Mix everything together. 
5 Pour the mixture into the muffin tin - the cups will be almost completely full. They will expand a lot in the oven, but shrink back down when you take them out, so it's ok. 
6 Place the muffin tin on a sheet pan and bake the egg cups for 20-25 minutes, until they're firm to the touch (but still a little squishy - not hard) and a little golden-brown on top. Let them cool completely before storing in the fridge. Enjoy them with English muffins, toast, bagels, wraps or on their own!