In a large bowl whisk the eggs, add the milk, a pinch of salt,1/2 teaspoon of pepper and whisk again.
Peel the sweet potatoes and cut them in 1/4 inch dice. Heat the oil in a 10-12 inch saute pan (I used my cast iron skillet). Add the potatoes and stir to coat. Sprinkle with the cumin, 1/2 teaspoon salt and the thyme and stir again. Cook the potatoes stirring occasionally until tender and browned - about 10 minutes. Sprinkle the green onions on the top and then the spinach.
Let the spinach wilt for about a minute, using a lid to help. Turn the heat to low, whisk the eggs again and pour over the top. Crumble the goat cheese over the top. Place the pan in the oven and bake for 10-12 minutes or until just set.
Remove the frittata and let it rest for a couple of minutes before slicing. Sprinkle with more pepper, garnish with cilantro and serve with hot sauce on the side.
You can use leftover roasted or cooked vegetables in place of the sweet potatoes. You want roughly about 3 cups. Just heat them through with the olive oil.1 tablespoon of fresh thyme equals 1 teaspoon dried thyme.