Peel potatoes and straighten/square the edges with a knife (see video for reference). This will make the potato easier to slice and result in straight cut chips. Slice potato into 6-8 thick wedges (bear in mind they will shrink slightly in the oven).
Add to a pot of cold water with 2 tsp salt. Bring to a boil for around 5-8mins, or until parboiled. The edges should begin to fluff and you should only JUST be able to slice through the potato.
Drain (don't rinse) in a colander and shake about to rough the edges. Allow to steam dry for 10-15mins, preferably until they stop steaming.
Meanwhile pour enough oil to cover the base of a baking tray. I use 1/3cup/80ml in a 12"x15" tray for reference. Pop in the oven at 205C/400F until piping hot.
Remove tray and quickly but carefully add chips. Use a pair of tongs to coat the chips in oil, make sure they're spread out then pop in the oven for 35-45mins, turning a few times throughout until golden brown and crispy. Important to space chips out or they'll steam and go soggy. Timings will depend on thickness of chips so just be vigilant. Place on paper towels to soak excess oil once cooked.
Butter one side of each of your slices of bread. Add chips to two of those slices, top with a pinch of salt, drizzle with vinegar (optional) then add ketchup. Add the second slice of bread, slice in half and enjoy!
Quick Demo
Notes
a) Can I use frozen chips? - If after all this I haven't convinced you to make your own chips, you can bake some oven chips and use them. Go for thick/steak cut chips and make surely they're nicely crisp (to counter the soft bread). About 6-8 chips per sandwich should suffice!b) Oil - It's important to use an oil with a high smoking point (like canola, veg or sunflower oil). You want it piping hot before you add the chips. Olive oil is not suitable as it'll just smoke out the kitchen.c) Calories - based on tbsp oil, 1 tsp salt, 2 tbsp butter and 2 tbsp ketchup in total. Calories per sandwich:
* Percent Daily Values are based on a 2000 calorie diet.
*Nutrition is based on the absence of salt unless stated as a measurement in the ingredients. Cost is worked out based on ingredients bought from UK supermarkets, then divided by the number of servings. In both instances these values are just for guidance. Please check out my FAQ Page for more info.