Preheat oven to 350 degrees F. While oven is preheating, heat up your cast iron skillet over medium heat and add butter.

Slice up onion into half moon shape. So, cut it in half and then slice it long ways. And add the onions to the preheated cast iron skillet with butter.

Sauté the onions until they start to become translucent and soft.
While the onions are cooking, prepare the egg mixture.

In a In a bowl, whisk together the eggs, heavy cream, and salt. Shred the entire block of cheese and fold into the egg mixture.
Slice the garlic thinly and add to the skillet. Give a quick toss. Add the artichoke hearts.

Evenly distribute the onions, garlic, and artichoke hearts in the pan and remove from heat.
Now, you’ll begin to layer in the remaining ingredients. Start adding in the olives evenly around the pan. Then layer the sliced tomatoes on the top.

Pour egg mixture over the vegetables and add the skillet pan to the oven.

Bake for about 20-30 minutes. Or until eggs are set. A good rule of thumb to prevent overcooking — check about 10 minutes before the frittata is supposed to be done.

To add a little bit of golden brown “crust” to the top, add a handful of shredded cheese. This is optional, but I like to use shredded Parmesan cheese for the topping. You can also add the frittata under the broiler for about 2-4 minutes.

Be really careful not to overcook it.
Allow to cool for about 10 minutes, cut into wedges. And enjoy!