The first thing you need to do is make sure you have the right potatoes for roasting – Yukons are great, and those little Yukon Creamers are especially good.
Try and pick potatoes that are roughly the same size, to ensure even cooking. Slice in half and place into a big bowl and wash really well – swirl them round and round, using your hands to swish them roughly in lots of cold water. This will release some of the starch and make them a lot creamier after cooking.
Dry well (the won’t brown if they’re wet), then toss into a bowl. Sprinkle generous amounts of garlic powder, onion powder, paprika, cracked pepper and salt (smoked salt is great, too) on top, add about 1-2 tbsp of oil (you’d be surprised how little you need to evenly coat a pound or two of potatoes).
Line your largest cookie sheet with parchment paper and spread out the potatoes in a single layer – they won’t cook properly/evenly if they’re piled on top of each other. Bake at 425 F for 20mins, turn and return to the oven for another 10-20 mins. Test with a fork for doneness, and be careful not to overcook or they’ll be dry.