1. Place potato in a small saucepan with enough water to cover; season with salt. Place over high heat and bring to a boil. Cook until tender, 45 to 60 minutes. Drain and peel.

2. Immediately transfer potato to a medium bowl and crush into 1/4-inch pieces using a fork.

3. Heat butter in a small skillet over medium heat. Add onion and cook until soft and translucent. Add to bowl with potato, along with cheese; season with a pinch of salt and nutmeg. Stir until just combined.

4. Heat a 5- to 6-inch square cast-iron skillet over high heat. Add enough grapeseed oil to coat bottom of skillet; remove any excess oil and discard. Add potato mixture and cook until golden brown, about 5 minutes. Using a spatula, turn frico and continue cooking 5 minutes more.

5. Meanwhile, in a small bowl, whisk together shallots, cilantro, vinegar, and 2 tablespoons grapeseed oil; season with salt. Cut frico into 4 wedges and place each on a serving plate, along with salad greens topped with radishes, and sliced speck. Drizzle vegetables with cilantro vinaigrette; serve immediately.