Preheat your oven to 375°F (190°C).

In a large skillet, warm up some olive oil over medium heat.

Add the diced potatoes and cook until they’re tender and starting to brown, about 10-15 minutes, stirring occasionally.

Toss in the chopped onion and minced garlic, cooking until the onion is translucent and fragrant.

In a mixing bowl, whisk together the eggs, milk, salt, and pepper until combined.

Spread the cooked potato mixture evenly in the skillet, then pour the egg mixture on top. Sprinkle the shredded cheese over everything.

Cook on the stovetop for about 5 minutes until the edges start to set.

Transfer the skillet to the oven and bake for 20-25 minutes until the top is golden brown and the frittata is spongy to the touch.

Allow to cool slightly before slicing.

Serve warm, garnished with fresh herbs if desired.