For the asparagus purée:
1/2 cup kosher salt, plus more for seasoning
5 medium asparagus spears
3 Tbs. extra-virgin olive oil
Freshly ground black pepper
For the roasted asparagus:
2 Tbs. canola oil
16 medium asparagus spears
Freshly ground black pepper
Kosher salt
2 Tbs. unsalted butter, diced
2 Tbs. extra-virgin olive oil
1 lemon
For the asparagus purée:
Put salt and two quarts water in a large nonreactive pot and bring to a boil over high heat.
Place five asparagus spears in the boiling salt water for five seconds. Remove them from the pot and place in a bowl of ice water for one minute. Reserve half a cup of ice water. Cut the spears into one-inch pieces.
Place them in a blender. Blend on high, adding just enough ice water to make the blender operate. Slowly add the olive oil and blend until smooth. Add salt and pepper to taste.
For the roasted asparagus:
Put the oil in a cast-iron skillet and heat over high until the oil smokes. Add asparagus in one-layer batches to the skillet. Let asparagus caramelize, turning once, about one minute. Generously sprinkle with salt and pepper. Add the butter and let it foam for 20 seconds. Remove the asparagus from the skillet and place on paper towels.
To serve, divide the purée among four eight-inch plates. Smear it across the plate with a spoon. Drizzle olive oil in a circle and place the hot asparagus on the purée. Finish with a squeeze of fresh lemon juice. Serve.
