How to Make It
Preheat the oven to 225°. Bring a medium saucepan of water to a boil. Add the potatoes and boil over high heat until tender, about 10 minutes. Drain well. Pass the potatoes through a ricer into a bowl.
In the same saucepan, cook the butter over moderate heat until browned and nutty, about 4 minutes. Stir in the potatoes and nutmeg and season with salt and pepper. Keep the potato puree warm over low heat.
In a food processor, pulse the panko until fine. Dust all but the asparagus tips with the flour. In a pie plate, beat the eggs. In another pie plate, add the panko and season with salt and pepper. Dip the floured part of the asparagus in the egg, then dredge in the panko.
In a deep skillet, heat the canola oil until shimmering. Fry the asparagus in batches over moderately high heat, turning, until golden and crisp, about 3 minutes. Drain on paper towels and sprinkle with salt. Keep the asparagus warm in the oven.
In a small skillet, heat 1 tablespoon of the olive oil until shimmering. Add the shallot and cook over moderate heat until softened, about 3 minutes. Scrape the shallot into a bowl. Whisk in the tomato paste and vinegar, then whisk in the remaining 6 tablespoons of olive oil. Add the herbs and chopped eggs to the dressing and season with salt and pepper. Add the watercress and toss to coat.
Spoon the potato puree onto plates. Top with the asparagus and salad and serve.