Sausage, green onion, and cheddar cheese egg "muffin"

If you're on Pinterest, you've seen these egg "muffins" floating around. They have a lot going for them:

They're a make ahead homemade breakfast. Just pop one in the microwave and eat!
No carbs, but they're filling from the protein rich eggs, breakfast meat, and/or loads of veggies you can add to them.
You only have to wash breakfast pots and pans once a week.
The recipe variations are endless.

I'll give you the links to a couple of different sites where I reviewed and tweaked recipes from:

Here's what I ended up with.

Sausage, Green Onion and Cheddar Cheese Egg "Muffins"

Ingredients

1 pound breakfast sausage, cooked and cooled
1/2 cup to 1 cup sharp cheddar cheese, grated
1 large green onion, finely chopped
8 large eggs
1/4 cup milk
1/2 teaspoon baking powder
1/2 teaspoon salt
1/4 teaspoon pepper
handful of chopped herbs (I used marjoram, rosemary and basil)

Directions

Preheat the oven to 375 F. Spray your 12 cup muffin tin with non-stick cooking spray. Evenly distribute the breakfast sausage, cheddar cheese and green onions into the muffin tins. In a large mixing bowl, combine the eggs, milk, baking powder, salt, pepper and chopped herbs. Divide the egg mixture evenly into the muffin tins.

Bake the "muffins" for 15-20 minutes until just set. Cool completely and keep refrigerated until breakfast time. Reheat and enjoy!