Incredibly crispy potatoes, only 2 ingredients, potatoes and starch, try it

INGREDIENTS:
2 potatoes (600 g).
Water.
A teaspoon of salt and dried tomatoes with garlic.
150 g corn starch.
vegetable oil.
Roasted golden brown.
For a quick sauce: green dill.
100-120 g sour cream or natural yogurt.
1 clove of garlic.
A pinch of salt and pepper.
A little (a tablespoon) of lemon juice