How to Make It
Whisk lemon zest and juice, salt, ¼ cup oil, and black pepper in a large bowl. Stir in ¼ cup mint.
Cook pasta according to package directions. Add asparagus during the last 3 minutes of cooking. Drain and cover to keep warm.
Meanwhile, halve leek lengthwise and thinly slice crosswise into half-moons (about 2 cups). Place in a medium bowl filled with water and let stand for 1 minute, stirring occasionally. Lift leek slices from water (leaving any grit behind) and drain on paper towels.
Heat 2 tablespoons oil in a large skillet over medium-high. Cook leeks, stirring occasionally, until tender, about 4 minutes. Add lemon mixture, pasta, and asparagus to skillet with leeks and toss to combine. Serve topped with cheese, crushed red pepper, and remaining ¼ cup mint. Drizzle with remaining 2 tablespoons oil.