Peel the potatoes and slice them thinly. The thinner your slices, the more delicate your final torta will be.

In a deep 10-inch frying pan, pour enough olive oil to completely cover the potatoes. Add the sliced potatoes, chopped garlic, and chopped onion.

Cook everything uncovered over medium-low heat until the potatoes become tender but not browned, about 15-20 minutes.

Once potatoes have softened, drain off most of the oil, saving about 2 tablespoons for later use. Allow the potato mixture to cool slightly.

In a large bowl, whisk together the eggs and milk. Add the drained potato mixture and let everything rest together for about 10-15 minutes to allow the flavors to combine.

Season generously with salt and freshly ground black pepper, remembering that potatoes absorb quite a bit of salt.

Heat a 10-inch non-stick frying pan with the reserved olive oil. Pour in your egg-potato mixture and cook over low heat until the eggs are mostly set but the top is still slightly runny.

Test doneness by inserting a fork—it should come out clean from the bottom portion.

Using a large plate or pan lid, carefully invert the torta, then slide it back into the pan to finish cooking the other side until golden and fully set.

Alternatively, you can finish cooking the torta in a 400°F (200°C) oven until the top is set if you prefer not to flip it.

Allow to cool slightly before slicing and serving.