Ingredients
Scale
- 4 large russet potatoes (about 2 pounds), peeled
- 1 large yellow onion, thinly sliced
- 8 ounces cremini or button mushrooms, sliced
- 3 tablespoons unsalted butter, divided
- 2 tablespoons olive oil, divided
- Salt, to taste
- Freshly ground black pepper, to taste
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
- 1 tablespoon white wine vinegar or apple cider vinegar
- Optional: 1 clove garlic, minced (for mushrooms)
- Optional substitution: Yukon Gold potatoes can be used for a creamier texture
- Optional substitution: Use shallots instead of onions for a milder sweetness
Instructions
- Start by parboiling the potatoes: place the peeled potatoes in a pot of cold, salted water and bring to a boil. Cook for about 10 minutes until just tender but not falling apart. Drain and let cool completely, ideally overnight in the fridge. This step is key for achieving the perfect texture.
- Once cooled, grate the potatoes using a coarse grater. Place the grated potatoes in a clean kitchen towel and squeeze gently to remove excess moisture. Mama Lou always said, “Moisture is the enemy of crispiness!”
- Heat 1 tablespoon of butter and 1 tablespoon of olive oil in a large skillet over low heat. Add the sliced onions and a pinch of salt. Cook slowly, stirring occasionally for about 25-30 minutes until they turn golden brown and sweet. This part requires patience, but it’s the heart of the dish — just like when Mama Lou would hum softly as she stirred her onions.
- While the onions caramelize, heat the remaining butter and olive oil in another skillet over medium heat. Add the mushrooms and sauté for 6-8 minutes, stirring occasionally. Add garlic and thyme during the last 2 minutes. Finish with a splash of vinegar to brighten the flavors, then season with salt and pepper to taste.
- To make the rösti, heat a non-stick skillet over medium heat and add a tablespoon of butter. Add half of the grated potatoes in an even layer, pressing down gently with a spatula. Cook for about 8-10 minutes until the bottom is golden and crisp.
- Carefully flip the rösti using a plate or large spatula — this is a fun moment to practice your kitchen skills! Add a little more butter if needed, then cook the other side for another 8-10 minutes until golden and cooked through.
- Repeat the process with the remaining grated potatoes to make a second rösti.
- To serve, spread a generous layer of caramelized onions on top of each rösti, then pile on the sautéed mushrooms. Sprinkle with fresh thyme if you like, and enjoy immediately while warm and crispy.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Main Dish
- Method: Cooking
- Cuisine: International
