Cut potatoes into matchsticks, about 1/4" thick, and let it cook briefly in boiling water for about 30 seconds. Throw away the starchy water and pat dry the potatoes. Removing the starch helps the potatoes to crisp.
Make sure you have already dried your potatoes as much as you can before this step. Combine olive oil, smoked paprika, salt and pepper with the potatoes, and lay them out flat on a non-stick baking tray (you can line it with parchment paper if you prefer).
Bake at 200C/400F for 30 minutes, flipping once halfway. You may need slightly less/more time depending on your oven so do check it when it's almost 30 minutes.
Sprinkle some parsley flakes once they're out of the oven if you have them, and enjoy your yummy, can't-stop-eating-them fries! :)
You can replace smoked paprika with other varieties of paprika if you don't have it on hand.