Combine all ingredients in a small bowl. Cover and set aside at room temperature for 12 hours.

Line a strainer with linen towels and rest it over a large bowl. Pour mixture into the lined strainer. Place another linen towel on top, then place a heavy item such as a pot of water over top, to press the yogurt.

Store in an airtight container for up to 1 week.

Using a turner slicer, slice potato to create long ribbons. Starting with one strand, wind the long potato strand around itself, alternating directions, until it’s the size of a golf ball. Repeat to make 3 more balls.

In a deep fryer or deep saucepan, heat oil to 135°C (275°F). Using heatproof kitchen tweezers, carefully lower a potato ball into the oil and deep-fry for 1 minute or until golden and crispy. Transfer potato to a plate lined with paper towels to drain and immediately season lightly with salt. Repeat with remaining balls.

Line a dehydrator with paper towels, add potato balls, and dry at 60°C (140°F) for 2 hours.

Lay a potato ball, the flattest side down, on each of 4 small plates. Dot the top of each potato ball with crème fraîche and sprinkle with chives. Top with caviar and serve.