Japanese Sweet Potatoes Recipe

Preheat and prepare potatoes

Preheat oven to 425°F (220°C). Wash the Japanese sweet potatoes thoroughly and pat dry. Leave skins on. Cut each potato into 3/8–1/2 inch thick rounds or 1-inch thick wedges, keeping pieces uniform for even cooking.

Season potatoes

Place cut potatoes in a large bowl. Drizzle with 2 tbs olive oil, then add 1 tsp salt and 1/2 tsp black pepper. Toss to coat evenly.

Roast with sumac seasoning

In a small bowl, combine 2 tsp ground sumac, 1 tsp smoked paprika and 1/2 tsp garlic powder. Sprinkle the spice mix over the oiled potatoes and toss so the sumac mixture adheres to all pieces. Arrange potatoes in a single layer on a rimmed baking sheet lined with parchment or a silicone mat, leaving space between pieces for crisping.

Roast

Roast in the preheated oven 22–28 minutes, flipping once halfway through, until edges are golden and centers are tender when pierced with a fork. For crispier edges, broil 1–2 minutes while watching closely.

Cook aromatics

While potatoes roast, heat 1 tbs extra-virgin olive oil in a small skillet over medium-low heat. Add the finely minced shallot and cook 3–4 minutes until softened and translucent, stirring occasionally. Add the minced garlic and cook 30 seconds until fragrant, taking care not to brown.

Make sauce

Reduce heat to low and add 1/2 cup heavy cream to the skillet. Stir and bring to a very gentle simmer for about 1 minute. Whisk in 2 tbs mascarpone (or cream cheese) until fully incorporated and the sauce is smooth. Add 1 tsp fresh lemon juice, 2 tbs grated Parmesan, 2 tbs chopped fresh basil, 1/4 tsp salt and 1/8 tsp black pepper. Stir and warm through just until sauce slightly thickens, about 1–2 minutes. Taste and adjust seasoning; if too thick, thin with up to 1–2 tbs water or milk.

Keep warm

Keep the sauce over the lowest heat or transfer to a warm bowl until the potatoes are ready. Stir occasionally to prevent skin forming.

Transfer roasted Japanese sweet potatoes to a serving platter. Spoon the creamy Italian sauce over the warm potatoes in an even layer or serve sauce on the side for dipping.

Scatter 2 tbs toasted pine nuts or chopped walnuts over the sauced potatoes. Sprinkle an additional 1/2 tsp ground sumac across the top for bright acidity and color. Tear 6 fresh basil leaves and scatter them as a final garnish.

Serve immediately while warm. Leftovers: store sauce and potatoes separately in airtight containers in the refrigerator up to 3 days; reheat potatoes in a 400°F oven to crisp, and rewarm sauce gently on low heat, adding a splash of cream or water if needed.