I had been making these for some time, not knowing the name for them until I learned that this thin style of oven crisped roasted potatoes was called “cottage fries” If you have a food processor all you need to do is feed the potatoes through the slicing disc (about 1/8 inch thickness) and just like that they are ready to bake. Otherwise just use a large chef's knife to slice thinly and evenly. The keys to getting crisp fries is to slice thin but not too thin, patting the sliced potatoes dry and making sure to bake them in a single layer, even if it means having to bake them in batches. You can use russet potatoes if you like, however I find Yukon gold makes for a lovely taste and texture. I don't recommend using red potatoes as they're texture is too mealy for these.

Preheat oven to 400 F. Thinly slice potatoes (about 1/4 inch or less) using a chef’s knife or slicing disc on food processor. Pat sliced potatoes dry with paper towels or a tea towel.
Line baking sheet with parchment paper and evenly spread potatoes in a single layer out on sheet. Bake until golden and crispy, about 15 minutes then flip and bake another 15-25 minutes. Repeat with remaining potatoes.
Ingredients
Directions
Preheat oven to 400 F. Thinly slice potatoes (about 1/4 inch or less) using a chef’s knife or slicing disc on food processor. Pat sliced potatoes dry with paper towels or a tea towel.
Line baking sheet with parchment paper and evenly spread potatoes in a single layer out on sheet. Bake until golden and crispy, about 15 minutes then flip and bake another 15-25 minutes. Repeat with remaining potatoes.