Preheat the oven to 350°F to bake the frittata when it’s ready then add 2 tablespoons of olive oil to a deep, oven-safe skillet (10 inch skillet is ideal) over medium heat. Once hot, add the sliced onion and cook, stirring frequently for 5-7 minutes, until the onions soften and start to turn a golden amber color, but aren’t totally caramelized. Once they’re done, add the shredded sweet potatoes, and mushroom and stir to cook for 2-3 more minutes.
While the veggies are cooking, whisk the eggs together with coconut milk, salt, pepper, parsley, chives and cheese.
Pour the egg mixture evenly over the cooked veggies (do not stir) and let it cook over medium heat for 2-3 minutes until the edges and bottom of the eggs just start to set in the pan.
Transfer the entire skillet to the preheated oven and bake for 16-18 minutes, until a knife inserted in the center comes out clean or when the eggs reach an internal temperature of 160°F. If using, top with the remaining 1/2 cup of cheese and broil on high for 1-2 minutes until it’s melted and golden brown on top.
Serve warm or at room temperature with more fresh herbs, fresh arugula or hot sauce.