Bring a large pot of water to a boil, adding about 1 tablespoon kosher salt when nearly boiling.
Cook the pasta in the boiling water until just al dente, then drain, reserving 1 cup of pasta water.
Zest the lemons and set the zest aside in two portions.
In a jar or bowl, whisk together lemon juice, 5 tablespoons olive oil, Dijon mustard, 1 teaspoon kosher salt, and black pepper until well combined.
Warm 1 1/2 tablespoons olive oil in a large sauté pan over medium heat.
Add the thinly sliced shallots and garlic; sauté for 2 to 3 minutes until garlic turns lightly golden.
Stir in red pepper flakes if using, cooking for an additional 30 seconds.
Add the sliced asparagus and half of the lemon zest; season with salt and pepper and cook for about 3 minutes until asparagus is tender-crisp.
Remove the pan from heat and set aside while finishing other steps.
Add the hot cooked pasta to the asparagus mixture along with the lemon sauce, crushed walnuts, and nutritional yeast.
Pour in 1/2 cup of reserved pasta water and return the pan to medium-high heat.
Use tongs to toss the pasta vigorously, adding more pasta water as needed until the sauce is creamy and coats the noodles.
Stir in the remaining lemon zest, basil, parsley, and optional capers, olives, and white beans.
Toss gently and cook for an additional 30 to 60 seconds to warm through.
Season with extra salt and pepper to taste, drizzle with olive oil, and serve immediately.
