Equipment
Ingredients
Röstis
- 800 g sweet potatoes, peeled
- 8 g salt
- 30 g cornstarch
- 2 eggs, beaten
- 3 spring onions, finely sliced
- 120 ml neutral oil
Dill Mayonnaise
- 1 egg yolk, room temperature
- 10 g dijon mustard
- 15 ml lemon juice
- 150 ml neutral oil
- 15 g fresh dill, finely chopped, stems removed
- 1 garlic, grated into paste
Nutrition (per serving)
Method
Using the coarse side of a box grater, shred the peeled sweet potatoes. Toss them in a large bowl with the 8g of salt. Let stand for 15 minutes to draw out moisture.
While potatoes rest, prepare the mayonnaise. In a bowl, whisk the egg yolk, Dijon mustard, garlic, and half the lemon juice until smooth. Slowly stream in the oil, whisking constantly, until a thick emulsion forms. Fold in the chopped dill and season with salt and remaining lemon to taste. Refrigerate.
Transfer the salted sweet potatoes to a clean kitchen towel or cheesecloth. Twist and squeeze vigorously to remove as much liquid as possible. The drier the potato, the crispier the rösti.
In a clean bowl, mix the dried sweet potato shreds with the beaten eggs, cornstarch, sliced spring onions, and a pinch of black pepper. Mix until just combined.
Heat the frying oil in a heavy skillet over medium heat to 170°C/340°F. Working in batches, place mounds of the mixture (approx 80g each) into the pan and flatten gently with a spatula to 1.5cm thickness.
Fry for 3-4 minutes per side until deep golden brown and crispy. Monitor heat carefully; sweet potatoes contain sugar and can burn before cooking through if the heat is too high.
Transfer cooked röstis to a wire rack and sprinkle immediately with flaky salt. Serve warm with the chilled dill mayonnaise on the side.
Chef's Notes
- Sweet potatoes burn faster than white potatoes due to higher sugar content. Maintain medium heat rather than high heat.
- Using cornstarch instead of flour creates a lighter, gluten-free crunch that stays crispy longer.
- For perfectly uniform röstis, you can press the mixture into a ring mold directly in the pan, then carefully remove the mold before flipping.
- The dill mayonnaise can be made up to 2 days in advance; the flavor actually improves as it sits.
Storage
Refrigerator: 3 days — Store röstis and mayonnaise in separate airtight containers. Röstis will lose crispness.
Freezer: 1 month — Freeze cooked röstis in a single layer. Reheat from frozen in oven.
Reheating: Reheat röstis in an oven at 180°C/350°F for 10-12 minutes to restore crispness. Do not microwave.
