- Preheat your oven to 400°F (200°C). 
- In a large skillet, cook the chopped bacon over medium heat until crispy. Remove and set aside. 
- In the same skillet, sauté the diced onions in a bit of the bacon fat until soft and translucent. 
- Toss the diced potatoes with olive oil, salt, and pepper in a large bowl. 
- Spread the potatoes evenly in a greased baking dish. Top with cooked onions and half the cheese. 
- Cover with foil and bake for 30 minutes. 
- Remove foil, sprinkle with remaining cheese and cooked bacon. Bake uncovered for another 15–20 minutes until potatoes are tender and cheese is bubbly. 
- Garnish with chopped parsley before serving, if desired.