Preheat oven to 375 degrees and oil a pie pan.
Thinly slice sweet potato and lay into pie to form a crust on the bottom and sides, it’s okay to overlap a little.
Bake for 15 minutes.
While the “crust” bakes, heat oil over medium-high and saute onion, garlic for 4 minutes, add spinach/kale (and tomato if using) cook until spinach is soft. Drain excess liquid if needed.
In a bowl, whisk together eggs, cheese, milk, seasoning.
Spread spinach mixture evenly over sweet potato crust. (Sprinkle bacon pieces if using.)
Pour egg mixture over everything and bake for 35-40 minutes.