Tart, tannic whey, the liquid byproduct of strained yogurt, is bolstered with butter and vegetal fenugreek in this sauce from Garagistes restaurant in Tasmania, creating a tangy, rich canvas for creamy cold-smoked potatoes.
- 2 lb. small waxy potatoes
- 1⁄4 cup canola oil
- 5 sprigs thyme
- 2 bay leaves
- 2 cloves garlic, unpeeled
- Kosher salt and freshly ground black pepper, to taste
- 1 cup fine-grain oak or hickory wood chips (the type used for a stovetop smoker)
- 1⁄3 cup toasted sesame oil
- 1 (2"-piece) ginger, peeled and minced
- 1⁄4 cup thinly sliced garlic scapes or chives
- 2 pods green cardamom
- 1 qt. plain, full-fat yogurt, drained overnight (should yield about 1½ cups whey)
- 1 tsp. dried fenugreek leaves
- 10 tbsp. unsalted butter, cubed and chilled
- Herbs and wildflowers, such as hyssop, garlic, and thyme flowers (optional)
Heat oven to 350°. Toss potatoes, oil, thyme, bay leaves, garlic, and salt on a baking sheet; roast until tender, about 45 minutes, and transfer to an 8" square baking dish. Line the bottom of a roasting pan with ice; nestle dish with potatoes into ice. Place ½ cup wood chips in a small metal bowl. Using a blowtorch, light chips, stirring as needed, until all the chips are charred; blow out any embers that remain and nestle bowl into ice. Cover roasting pan with aluminum foil; let sit for 25 minutes. Repeat smoking process with remaining wood chips.
Heat 1 tbsp. sesame oil in a 1-qt. saucepan. Cook ginger until fragrant, 1–2 minutes. Add remaining sesame oil, the garlic scapes, salt, and pepper; let cool. Toast cardamom in a 2-qt. saucepan until fragrant, 1–2 minutes. Add whey from yogurt (save yogurt for another use) and fenugreek; boil. Reduce heat to medium; cook until reduced by two thirds, 18–20 minutes. Strain sauce through a fine-mesh sieve into a 1-qt. saucepan; heat over low. Slowly whisk in butter, salt, and pepper until emulsified. Spoon whey sauce on a serving platter and top with potatoes; sprinkle with garlic scape mixture, and, if you like, herbs and wildflowers.