Step 1

Set the oven rack to the lowest position and preheat your oven to 450 degrees F (230 degrees C).

Step 2

Halve or quarter the potatoes, place in a large pot and top with cold water. Add the baking soda, season heavily with kosher salt and bring to a boil over high heat. Cook until just fork tender, about 8 to 10 minutes, then drain and allow to air dry.

Step 3

Coat the bottom of a large rimmed baking sheet with 2 tablespoons of the oil and place on the bottom rack of the oven.

Step 4

Lightly crush the garlic cloves just to burst the skin and transfer to the pot the potatoes were boiled in along with the potatoes and remaining 2 tablespoons of the oil. Season with kosher salt and pepper. Using a rubber spatula or wooden spoon, gently toss the potatoes for 1 to 2 minutes to develop some of the potato starches.

Step 5

Carefully remove the baking sheet from the oven and place the potatoes on in a single layer. Roast until the underside of the potatoes is a deep golden brown, 20 minutes. Meanwhile, rub some oil onto the herbs and set aside. Flip the potatoes over, add the herbs to the pan and continue to roast until crisp and golden, 10 to 15 minutes.

Step 6

Remove the potatoes from the oven, immediately grate over the lemon zest and season with more salt and pepper. Transfer to a serving dish and serve with sour cream on the side.