By Sarah Kenney
In a bowl, whisk together the eggs, salt and pepper. Set aside.
In a seasoned cast iron skillet over medium-high heat, warm 1 teaspoon of the olive oil. Add the sausage and cook, crumbling with a wooden spoon, until browned, 8 to 10 minutes.
Drain the sausage on paper towels, then transfer to another bowl.
In the same pan over medium-high heat, warm 1 tablespoon of butter. Add the mushrooms and cook, stirring occasionally, until browned and tender, 8 to 10 minutes. Season with salt and pepper. Transfer to the bowl with the sausage.
In the same pan over medium heat, warm 1 teaspoon of the olive oil. Add half of the chard and cook, stirring occasionally, until wilted, about 2 minutes. Season with salt and pepper. Transfer to a bowl. Repeat with 1 teaspoon of the olive oil and the remaining chard.
Return the rest of chard, the sausage and the mushrooms to the pan and heat over medium heat for 1 minute. Pour in the egg mixture and cook about 2 minutes. Spoon out goat cheese and place dollops all over the top of the frittata. Using a rubber spatula, lift the cooked edges and allow the uncooked eggs to flow underneath. Continue cooking until the eggs begin to set, about 4 minutes more.
Place the entire pan in the preheated oven. Continue cooking until the top is set and the frittata looks nice and slightly browned on top, about 5 minutes. Let cool for a few minutes. Slice into wedges and serve.