Place the hazelnuts on a baking sheet and toast for approximately ten minutes, until fragrant and slightly browned. Set aside.
Add the potatoes to a medium pot with the leek and chicken stock. Bring to a boil and then reduce heat to simmer. Once your potatoes are soft (fork-test), put everything from the pot into a food processor, purée and reserve.
Increase the oven to 500°F.
Cut the asparagus and the fennel into 1-inch pieces and toss them with the olive oil, salt and pepper. Spread them evenly on a sheet pan. Roast them in the oven for 10 to 15 minutes, until brown on edges, but not soft. Remove from the oven, place in a food processor with the cleaned spinach, and pulse 4 to 8 times to achieve a rustic, rough-chopped look.
When ready to serve, combine the potato mixture and the asparagus mixture in a pot with the rice vinegar, cheese and spices and heat through. Garnish with one teaspoon of hazelnuts per serving and several drops of Cholula or your favorite bright red hot sauce.
Light enough to be served as a casual breakfast dish, but hearty enough to accompany a New York steak.