Preheat oven to 450 degrees F. Lightly oil a baking sheet or coat with nonstick spray.
Place potatoes onto the prepared baking sheet. Add vegetable oil; season with salt and pepper, to taste. Gently toss to combine.
Place potatoes, cut-side down, in a single layer. Place into oven and bake for 35 minutes, until golden brown and crisp, flipping halfway.
To make the garlic herb mixture, combine garlic, shallot, parsley and basil in the bowl of a food processor. Pulse until finely chopped. With the motor running, add olive oil in a slow stream until emulsified; season with salt and pepper, to taste.
Serve potatoes immediately, drizzled with garlic herb mixture.
Notes
Use a good quality sheet pan. A durable sheet pan is ideal – it will last for years with minimal wear and tear, and will help achieve even cooking and avoid warping at high temperatures.
Leave the skin on. With a good scrub, the skin can be left on the potatoes. The skin is a good source of fiber, adds texture and helps the potatoes stay moist inside.
Use firm potatoes. When purchasing fingerling potatoes, look for potatoes that are consistent in size (to ensure even cooking), about 2-4 inches in length, and are firm to the touch. Store in a cool, dark, well-ventilated area, preferably in a mesh bag.
Place potatoes cut-side down. Roasting the fingerling potatoes cut-side down will maximize direct contact to the baking sheet, creating that deeply golden brown, crispy, caramelized crust.
Avoid an overcrowded pan. The potatoes should be spread out in an even layer. An overcrowded pan will steam the potatoes instead!
Flip halfway. Don't forget to flip the potatoes at the halfway mark to ensure that all the sides get golden brown and crisp.
Add the olive oil slowly. When making the garlic herb mixture, add the olive oil slowly into the food processor with the motor running. This will allow the sauce to emulsify (blend) into a cohesive sauce rather than separate.