This frittata just might be the best I've ever made. The combination of wonderful flavors is unreal and so, so freaking delish!
Bake onions and squash for a total of 25-35 minutes. You’ll know they’re done when the onions are brown and caramelized, and the squash is fork tender. Remove from oven and set aside.
Place the diced bacon in a cold, heavy bottomed, oven safe pan (cast iron is ideal), and bring up to medium heat. Render the bacon until it's just beginning to crisp, about 5 minutes. You may desire to drain some of the bacon fat. Add the kale to the pan with a splash of water, and toss it around for a few minutes, then throw a lid on the pan and let it steam for 2-3 minutes, or until tender. (I didn't drain my bacon fat and did not add the splash of water.) Remove the lid and add the cooked onion and squash.
Pour the eggs over the bacon and vegetables and use a rubber spatula to spread them out evenly. Sprinkle the crumbled feta cheese over the top, then place the skillet in the oven at 400 degrees F. for 10-15 minutes, until puffed up and golden on the outside. The inside should be totally set. If it's still runny, place back in the oven for a few minutes more.
*I buy my butternut squash precubed (so much easier!).
FOR WHOLE30/PALEO/DAIRY-FREE: Leave out the feta cheese.