Peel and slice the potatoes. Cut larger potatoes into 6-8 pieces and smaller potatoes into 2-4.
Add the potatoes to a large pot and cover them with cold water. Generously salt the water, cover with a lid and bring to a boil.
Once boiling reduce the heat and simmer for 12 minutes. Drain and leave to steam dry for 5 minutes in the colander.
Preheat the oven to 210℃/190℃ fan (410℉/375℉).
Add the neutral oil to a large roasting dish and leave to heat up for 10 minutes.
Return the potatoes to the pot, replace the lid, and shake it a few times to fluff them up.
Once the oil is hot, add the potatoes to the roasting dish and season to taste with salt. Turn the potatoes so they are well coated in the oil.
Roast for 1 hour 10 minutes, or until golden brown and crispy. Turn the potatoes every 20-30 minutes.
Whilst the potatoes roast, combine the garlic, rosemary, and sage in a small bowl with the olive oil.
When the potatoes are almost ready, pour the garlic mixture over the potatoes and toss to coat. Roast for a further 5-6 minutes.
Use a slotted spoon to remove the potatoes from the roasting dish and allow to drain a little on kitchen paper. Serve hot, enjoy!
