Mini Make Ahead Frittatas

I am always looking for make ahead food for my toddler. I am a zombie in the morning so I don't want to have to think about what to make. Or lunch is a scrounge for yourself type day. Its not fair for the toddler to find his own lunch so this is a good option :)It would also be great for a fast breakfast before work.
I just adapted my other frittata recipe. The combinations are endless. Play around with it.

Sorry about the picture. I forgot to take one until they were already frozen.

Mini Frittatas
Makes 12 muffin sized

Ingredients:

2 tbsp butter or oil
2 russet potatoes, grated
1 onion, grated
8 eggs
2 tbsp milk or cream
1 tsp garlic powder
1 tsp dried basil
1 tsp dried oregano
1 tsp dried parsley
1 cup of cheese (I used feta, cheddar, and provolone, separately)
filling of choice. Ideas: mushrooms, asparagus, bacon, sausage, ham, spinach, zucchini, bell pepper, tomatoes

Preheat oven to 375

Dry the potato and onion very well after grating. Place in a large skillet that has been heated over medium heat, with butter melted.

Cook until starting to brown, stirring/flipping as needed. About 5-8 minutes.

Evenly divide potato mix between the muffin pans. Add whatever fillings you want. Put cheese on top.

Beat the eggs, milk, and spices well. Add a couple/few tbsp to each muffin pan.

Place in oven and cook 15-20 minutes or until golden brown and set. Let cool in pan. Eat or transfer to sheet pan and put in freezer for 2 hours and then move to freezer bag. This is so they don't stick together