We ended up having the frittata last night. I didn't have an onion, so I sauted the spinach and added in some garlic and Italian seasoning with it, then added in the roasted red peppers. Instead of parmesan I used feta and added a little more seasoning in with the eggs. Oh man, was it ever good! The regular recipe is good to begin with, but I really liked it this way. And I didn't miss the onions at all! I'll probably leave them out going forward when I make it.