In a large bowl, mix together the potatoes, onion, garlic, olive oil, rosemary, salt and pepper.
Spread the mixture onto a large baking sheet and bake in the preheated oven for 40-50 minutes, stirring occasionally, until the potatoes are tender and golden brown.
Serve immediately.
Interesting Facts
Rosemary is a fragrant, evergreen herb in the mint family.
Potatoes are a great source of energy and contain high levels of vitamin C.
Onions are a rich source of antioxidants and vitamin C.