There is something quietly magical about a golden, crispy rösti — that Swiss-born potato pancake that walks the line between rustic comfort and refined elegance. When paired with earthy, meaty eryngii mushrooms (also known as king oyster mushrooms) and a whisper of garlic and rosemary, it becomes the kind of dish that turns a simple dinner into a quiet celebration. This recipe, inspired by the Russian culinary site Gastronom.ru, calls for a clever parboiling and overnight chilling technique that guarantees the perfect texture: tender on the inside, shatteringly crisp on the outside. Whether you serve it as a hearty vegetarian main or a stunning side, these potato rösti with eryngii mushrooms are destined to become a favorite in your repertoire.
About the Dish
Rösti originated in Switzerland as a farmer’s breakfast, but today it is beloved across Europe and beyond. The key to exceptional rösti lies in the preparation of the potatoes: parboiling them whole, then chilling them for hours allows the starch to firm up, making it easy to grate into long, thin shreds that fry up into a lacy, golden crust. The addition of egg yolks and a touch of potato starch — a trick many home cooks overlook — helps bind the shreds without making them heavy. Here, we pair the rösti with eryngii mushrooms sautéed in clarified butter infused with garlic and rosemary. The mushrooms’ dense, almost scallop-like texture provides a savory counterpoint to the crispy potato. For more inspiration on working with similar textures, explore our guide to the best food processor for nut butters — though we use a mandoline for this recipe, a good processor can speed up grating.
Ingredients
- 1 kg (about 4–5 medium) waxy potatoes (such as Yukon Gold)
- 1 large egg
- 2 large egg yolks
- 3 tablespoons clarified butter (ghee), plus more for frying
- 1 tablespoon potato starch
- Salt and freshly ground black pepper to taste
- 4 cloves garlic, smashed
- 4 sprigs fresh rosemary
- 300 g eryngii (king oyster) mushrooms
- Sour cream, for serving
For the best results, use a non-toxic immersion blender or a mandoline for grating the potatoes — though for this recipe a mandoline is ideal for long, thin shreds.
Step-by-Step Instructions
Step 1: Parboil the Potatoes
Scrub the potatoes thoroughly under running water (no need to peel). Place them in a large pot and cover with cold water by about 2 inches. Bring to a boil, add a generous pinch of salt, and cook for exactly 10 minutes. Remove from heat and let the potatoes sit in the hot water for another 5–7 minutes. Drain, then transfer the potatoes to the refrigerator and chill for 8–12 hours (or overnight). This cooling step is crucial for firming the starch.
Step 2: Grate the Potatoes
Peel the chilled potatoes. Using a mandoline or the large holes of a box grater, shred them into long, thin matchsticks. Avoid gratings that are too fine — you want texture. Transfer the shreds to a large bowl.
Step 3: Mix the Batter
To the grated potatoes, add the whole egg, egg yolks, melted clarified butter (3 tablespoons), salt, pepper, and potato starch. Stir until everything is evenly coated. The mixture should be moist but not wet.
Step 4: Fry the Rösti
Heat a generous amount of clarified butter (about 2–3 tablespoons) in a non-stick or cast-iron skillet over medium heat. Using about 50–60 g of the potato mixture per patty, form neat, round cakes. Place them in the hot butter and flatten gently with a spatula. Fry for 4–5 minutes per side, until deep golden brown and crispy. Drain on paper towels.
Step 5: Infuse the Garlic and Rosemary Butter
In a separate small saucepan, combine the smashed garlic cloves, rosemary sprigs, and 3–4 tablespoons of butter (or more clarified butter). Warm over very low heat for 10 minutes to gently infuse the flavors. Do not let the butter brown. Strain out the solids, if desired, but leaving them in adds rustic charm.
Step 6: Prepare the Eryngii Mushrooms
Cut the eryngii mushrooms lengthwise in half. If they are very large, you may quarter them — aim for uniform pieces.
Step 7: Sear the Mushrooms
Increase the heat under the infused butter to medium-high. Add the mushroom halves and sear for 5–7 minutes, turning once or twice, until they are deeply browned and tender. Season with a pinch of salt.
Step 8: Assemble and Serve
Arrange the hot rösti on a warmed plate. Top each with a few pieces of the seared mushrooms. Serve immediately with a dollop of sour cream on the side. The contrast of crispy, creamy, and earthy is sublime.
Tips for Perfect Rösti
- Chill thoroughly: The overnight refrigeration is non-negotiable — it firms the starch and prevents the shreds from becoming mushy.
- Use clarified butter: Ghee or clarified butter has a higher smoke point, giving you a golden crust without burning.
- Don’t overcrowd the pan: Fry only a few cakes at a time to maintain high heat. If you need to cook in batches, keep finished rösti warm on a rack in a low oven.
- Season generously: Potatoes need salt to bring out their flavor. Add pepper for a subtle kick.
For those who love crispy textures, consider pairing these rösti with a side of non-toxic air fryer vegetables for a complete meal.
Variations
While this recipe is a classic, feel free to adapt: replace eryngii with chanterelles or shiitake for a different earthiness; add a handful of grated Gruyère or Parmesan to the potato mixture; or serve with a drizzle of truffle oil. For a vegan version, omit the egg and yolk and use a flax egg plus extra potato starch — though the texture will be slightly different. Explore our review of the best planetary mixer if you want to experiment with other doughs or batters.
FAQ
Can I use regular butter instead of clarified butter?
Yes, but the milk solids in regular butter will brown more quickly and may burn at high heat. Clarified butter (ghee) gives a cleaner, more consistent crust. If you’re using butter, watch the heat carefully.
Do I need to squeeze out the potato moisture?
Because the potatoes are parboiled and chilled, they are not overly wet. However, if you see excess liquid after grating, you can gently press the shreds in a clean kitchen towel. Do not over-squeeze — some moisture is needed for binding.
Can I make rösti ahead of time?
Rösti are best fresh and crispy. You can parboil and chill the potatoes up to 24 hours in advance. Once fried, they can be kept warm in a 200°F oven for 30 minutes, but reheated rösti may lose their crunch. Consider using a microwave pressure cooker to reheat gently if needed.
What can I substitute for eryngii mushrooms?
King oyster mushrooms are ideal for their meaty texture, but portobello, cremini, or even sliced shiitake will work. For a truly luxurious version, try chanterelles or morels. Check out our best chocolate-covered raisins for a sweet finish to the meal!
Is this recipe gluten-free?
Yes, as written (using potato starch), it is naturally gluten-free. Ensure your clarified butter and other ingredients are certified gluten-free if you have sensitivities.
Can I bake the rösti instead of frying?
Baking will yield a softer texture. For a crispy oven version, shape the patties and bake at 425°F (220°C) on a parchment-lined sheet brushed with oil, flipping halfway. For more oven tips, read our review of the best commercial countertop convection oven.
How do I store leftovers?
Store fried rösti and mushrooms separately in airtight containers in the refrigerator for up to 3 days. Reheat the rösti in a hot skillet to restore crispness; the mushrooms can be reheated in the microwave or skillet.
For more kitchen inspiration, explore our guides on undercounter ice makers and steam canners to round out your cooking tools.
Recipe adapted from Gastronom.ru. If you notice any errors, please let us know.
