1. Crumble the Cotija cheese to get 2 ounces, and grate Mozzarella (or use pre-grated Mozzarella)  Slice the green onion. ​

​

2. Beat eggs (with the milk or half-and-half if using) until the whites and yolks are well combined.

​

3. Adjust the oven rack so it’s about 4-5 inches under the broiler and turn broiler on.

​

4. Heat the oil in a heavy oven-proof frying pan over medium-low heat. 

​

5. When the pan feels hot when you hold your hand over it, add the eggs, season with Spike Seasoning (affiliate link) and fresh-ground black pepper,  and let eggs cook for about 2 minutes, just until they’re starting to look cooked on the edges.  (I usually take a rubber scraper and run it around the edges, but it’s probably not really necessary!)

​

6. Add the grated mozzarella and sliced green onion and cook about 5 minutes more, or until the eggs look like they’re cooked about half-way through.  (Actual cooking time will depend on your pan and how hot the medium-low setting is on your stove.  Turn to low if it seems like the eggs are cooking too quickly.)

​

7. Slice the avocado while the eggs are cooking.

​

8. When eggs are cooked about half-way through, lay the avocado slices over and sprinkle with the Cotija cheese.

​

9. Cover the pan with the lid and cook about 3 minutes more, or until the eggs look like they’re nearly cooked through and the Cotija is starting to melt.

​

10. Remove lid, put the frittata under the broiler and cook about 2 minutes more, or the eggs are firm and cheese is melted and the top of the frittata is nicely browned.  (Watch it carefully; it’s easy to get it too brown under the broiler!)

​

11. Serve hot.