Drain marinade from 1 jar of artichokes into a frying pan. Drain remaining artichokes, discard liquid, and chop all artichoke hearts into small pieces.
In a frying pan over medium heat, add chopped artichokes, onion and garlic. Cook until onion is soft, for about 5 minutes.
While artichokes are sauteeing, whisk eggs in a bowl. Stir in oregano, parsley, chopped spinach, parmesan cheese, cheddar cheese, salt, pepper and hot sauce (if desired). Add in artichoke mixture and combine until incorporated.
Pour everything into a greased 8x8 baking pan.
Bake frittata for 45 minutes, until set and golden brown.