Step 1

To begin, gather and prep all of your ingredients according to the ingredient list above to have ready and organized for use.

Step 2

Preheat oven to 350°.

Step 3

Place a cast-iron (10 inch) skillet, or other non-stick and oven safe skillet, over medium-high to high heat, and add in the butter and the oil. Once the butter has melted, add in the sliced onions, and allow them to caramelize a little, for about 10-12 minutes.

Step 4

Then, add in the sliced shiitakes, and continue to cook until the mushrooms become golden-brown, about 4 minutes. Add in the chopped baby broccoli and stir that in to incorporate, and allow the broccoli to become crisp-tender, about 3 minutes or so.

Step 5

Add in the garlic, a couple of pinches of salt and pepper, the Italian seasoning, and the chopped parsley and cilantro, and stir to combine. Once the garlic becomes aromatic, turn the heat to very low, or turn off for a moment.

Step 6

Whisk together the eggs, the half &half, a couple of pinches of salt and black pepper, the pinch of cayenne (if using), and about 1 cup of the grated cheese, whisking only until then eggs are broken up, taking care not to over-whisk.

Step 7

Now, with the heat turned up under the skillet to medium-high, pour in the egg mixture and gently stir with the sauteed vegetables to incorporate. Then, allow the egg/veggie mixture to cook, undisturbed, for about 2-3 minutes, or just until the sides begin to set up.

Step 8

Sprinkle the remaining 1/2 cup of cheese over top, and place the skillet into the oven to bake for about 24 minutes, or just until the frittata is puffed and set. Allow for a few minutes out of the oven before slicing and enjoying.