Smashed Potatoes — Fried or Baked

Place potatoes in a large pot and cover with cold water by 2 inches. Add kosher salt and baking soda. Bring to a boil over high heat, then reduce to a steady simmer. Cook until a knife slides through with zero resistance, about 15–18 minutes. The baking soda roughens the surface starch — don't skip it.

Drain and spread onto a wire rack in a single layer. Let sit uncovered for at least 10 minutes until the surface is visibly dry and matte with no steam rising. Wet potatoes steam instead of crisp regardless of method.

Working one at a time, press each potato firmly with the flat bottom of a heavy skillet to about 1/2" thick. Jagged edges and craggy surfaces are good — that's where the crust develops.

Preheat oven to 450°F with a large rimmed baking sheet inside. Whisk together olive oil (or brown butter) and Dijon in a small bowl. Toss smashed potatoes in the mixture until coated. Carefully slide onto the screaming-hot pan in a single layer — you should hear an immediate sizzle.

Roast at 450°F for 20 minutes until the bottom is deeply golden. Flip with a thin metal spatula and roast another 15–20 minutes until crisp and amber on most sides. While potatoes roast, warm a splash of oil in a small pan over medium and fry the garlic cloves and rosemary sprigs until golden and crisp, about 90 seconds. Set aside for finishing.

Combine neutral oil and tallow/duck fat in a large deep cast iron or Dutch oven. Heat to 325°F. Fry smashed potatoes in batches — don't crowd — until just barely blonde and cooked through, about 4 minutes per batch. Transfer to the wire rack. Let oil return to temp between batches.

Let first-fried potatoes rest on the rack for at least 5 minutes. Interior moisture redistributes and the surface firms — this is what makes the second fry dramatic.

Raise oil to 400°F. Drop garlic and rosemary into the hot oil and fry 60–90 seconds until garlic is golden and rosemary is crisp. Remove and set aside. Working in batches, fry rested potatoes at 400°F for 2–3 minutes until deeply amber and audibly crackling. Pull the moment they hit rich golden brown — color moves fast. Transfer to wire rack, never paper towels.

While potatoes are still screaming hot, hit them with the flaky salt, a generous microplane of lemon zest, and a squeeze of lemon juice. Scatter the fried garlic and crispy rosemary over the top. Serve immediately — these do not wait.