I'll share not only the basic "alla Toscana" way, but my secrets to have them really perfect with zero effort.
Ingredients:
Rooster potatoes - as many as you need
Dry rosemary - a lot, of course depending on how many potatoes you use (I'd say 1 Tbsp per 500gr potatoes)
Fine salt (best if freshly milled)
Freshly ground black pepper
Extra virgin olive oil
You'll need:
A big bowl or a big pot
A baking tray
Method:
Peel the potatoes and cut them into small pieces of roughly 1.5cm. Regardless of their shapes, it's important they are all of a similar size
Wash the pieces at least twice in fresh water, draining well each time
Put the potatoes into the big bowl or the pot and cover with water (1cm above the top), add 1 tsp of fine salt (any salt will do here) and mix well
Cover and let it stand for a minimum of 30 mins and up to 6 hours (which is super handy for dinner parties!)
Pre-heat the oven at 200 degrees C (fan)
Drain the potatoes well and put them back into the same bowl
Add a sprinkle of salt, black pepper, rosemary and olive oil and mix very well
TIP: Don't add too much oil, just enough to coat them evenly
There must be enough rosemary and black pepper to be visible all around them after mixing
Put the potatoes onto a baking tray in a single layer and drizzle them with any remaining condiment from the bowl
Cook for 20-25 mins or until browned enough