1. Sprinkle the rye flakes, sugar and pistachios on a dry frying pan and toast the mixture over a high heat for about 2 min., then reduce to a medium heat and continue toasting for about 5 more minutes, stirring occasionally.
2. Set the flakes aside to cool.
3. Combine the orange fillets and passion fruit. Place the skyr in bowls and top with the fruit and flakes.
4. Serve immediately.