Preheat the oven to 400°F and move the rack to the middle position

In a small bowl, whisk together eggs, heavy cream, and a pinch of salt. Set aside

If using bacon, cook in a medium cast iron skillet over medium-high heat until crisp (8–10 minutes). Transfer to a paper towel-lined plate and remove all but 2 tablespoon of fat. If not using bacon, heat 2 tablespoon oil instead

Return the pan to medium heat and add sliced potatoes. Season with salt and pepper. Cook, stirring occasionally, until tender and lightly browned, about 10 minutes

Add the spinach and garlic. Cook, stirring, for 30–60 seconds until spinach begins to wilt

Add the cooked bacon back into the pan, stir to combine

Spread the mixture into an even layer and flatten with a spatula

Sprinkle cheese over top

Pour egg mixture over everything, tilting the pan slightly to distribute

Cook for 2 minutes until eggs begin to set at the edges

Transfer pan to oven and bake until eggs are fully set, about 10–12 minutes

For a crisp top, broil for 60–90 seconds

Let cool for 5 minutes, slice into wedges, and serve