Butternut Squash and Potato Rösti with Mustard Butter

Peel the butternut squash and potato. Using a box grater or food processor, shred both into rough, even strands. Place in a large bowl.

Peel and grate the yellow onion. Squeeze out excess moisture with a clean kitchen towel or your hands — this prevents soggy rösti.

Add the grated onion to the bowl with the squash and potato. Season with salt and black pepper, then crack in the egg. Toss everything together until evenly combined.

Heat a cast-iron skillet over medium heat. Add sunflower oil and let it shimmer, about 1 minute.

Divide the vegetable mixture into 4 equal portions. Press each firmly into a flat disc about 2cm thick, squeezing out any remaining liquid.

Add one rösti to the hot oil. Fry 4-5 minutes per side, until deeply golden and crisp at the edges. Press gently with a spatula for even contact. Repeat with remaining portions, adding oil as needed.

Transfer finished rösti to a paper-lined plate. Keep warm in a low oven (80°C) while you make the sauce.

In the same skillet (no need to clean), melt butter over medium heat. Swirl gently until it begins to turn golden and smell nutty, about 2 minutes — watch it closely, do not let it burn.

Remove from heat. Stir in mustard and chopped parsley. The residual heat will mellow the mustard slightly. Return to low heat for 30 seconds, stirring, until the sauce is smooth and glossy.

Plate each rösti and spoon the mustard butter generously over the top. Serve immediately while crisp and the butter is still glossy.