In a medium skillet, toast the walnuts over medium heat, stirring frequently so they don't burn, until they are toasted and fragrant, 4 to 6 minutes. Remove to a cutting board, let cool, then coarsely chop.
Wipe out the skillet and add the bacon. Cook over medium heat, flipping occasionally, until brown and crispy, 5 to 7 minutes. Transfer to a paper-towel lined plate to cool; crumble.
Bring 2 cups water to a boil in a large pot fitted with a steamer basket. Fill a large bowl with ice water. Add the asparagus to the basket and steam until tender, 3 to 4 minutes; immediately transfer to the ice water to stop the cooking. Pat the asparagus dry with a clean kitchen towel or paper towels.
In a large bowl, combine the asparagus, radishes, parmesan, herbs, and walnuts. Season with ½ teaspoon salt.
In a small mason jar, combine the oil, mustard, honey, lemon zest, lemon juice, shallot, pepper, and remaining ¼ teaspoon salt. Secure the lid and shake vigorously to combine. Drizzle over the asparagus mixture and toss to coat.
Transfer to a serving bowl and sprinkle with the bacon and more parmesan and herbs.
