Preheat the oven to 420 degrees F (215 degrees C). Line a baking sheet with parchment paper.
Place cubed potatoes in a large bowl and cover with cold water. Soak for at least 5 minutes.
Drain water from potatoes and pat potatoes dry with paper towels or a clean kitchen towel. Return potatoes to the bowl and add 2 tablespoons olive oil and generous pinches salt and pepper. Transfer potatoes to the prepared baking sheet and spread them out evenly.
Bake in the preheated oven until browned on the bottom and edges, about 35 minutes.
Meanwhile, prepare the chimichurri; combine parsley, basil, garlic, 2 tablespoons olive oil, vinegar, and a pinch salt in a bowl. Stir together and let sit while potatoes finish baking.
Remove potatoes from the oven and transfer to a large serving bowl. Add chimichurri to hot potatoes and mix until covered.