Russian
Peel the potatoes, cut them into slices or sticks about 4 mm thick, rinse in cold water and pat completely dry with a towel.
Halve the onion and slice it into thin half-rings.
Heat the oil in a large heavy frying pan (28 cm or more) over medium-high heat until it shimmers, and add the potatoes in an even layer.
Fry without stirring for 7-8 minutes, until a golden crust forms underneath, then turn the potatoes with a spatula.
Keep frying for 10-12 minutes, turning every 3-4 minutes, until most pieces are golden and tender.
Add the onion, season with salt and pepper and fry for 5-7 minutes more, turning twice, until the onion is soft and browned.
Take off the heat, sprinkle with the dill and serve hot.