Preheat oven to 425 degrees F.
In large cast-iron skillet, add pancetta and cook over medium heat until crispy, about 5-7 minutes.
Remove pancetta from skillet, leaving the fat.
Add the diced sweet potato, cumin, and salt and pepper and saute over medium heat until sweet potato is tender, about 10 minutes. Add the spinach then stir until wilted.
Add green onion and pancetta to skillet and remove from heat.
Whisk together eggs and milk, then pour over sweet potato mixture in the skillet. Sprinkle cheese on top.
Bake in preheated oven 15-18 minutes, until middle is just set.
Let sit for a couple of minutes, then slice and serve. Enjoy!