Preheat oven to 400 degrees.
Bring a large pot of salted water to boil.
Scrub potatoes and cut into 1 1/2-inch cubes.
Place potatoes into pot and remove with a slotted spoon as soon as water comes back to boil.
Spread potatoes on a large sheet pan, sprinkle with salt, pepper, garlic, rosemary and olive oil. Toss to coat evenly.
Roast until potatoes are nicely browned and tender, 30 to 45 minutes.
The secret to tender, crusty roast potatoes is to use plenty of olive oil.
Makes 12 to 16 servings