If you're after the ultimate in crispy and crunchy homemade potato wedges, then it's so important to par boil them before cooking. Par boil for 10 minutes or until just tender (but not soft). Drain the potatoes and then place back into the pot over the heat and shake until absolutely no moisture remains, then coat in butter and oil and roast. You may notice that some little bits of potato will fall off when you shake the pot and that's completely fine... those bits will become extra crispy little bites! Par boiling semi-cooks the inside of the potatoes, meaning that once they're roasted, the outside will be extra crunchy while the inside will remain deliciously soft and fluffy.