Bring a large pot of water to a gentle boil and prepare an ice bath in a large bowl on the side. Working in two batches, add the asparagus to the boiling water and cook until just tender, about 5-7 minutes. Be careful not to overcook the asparagus as they will lose their shape and start to wilt. Transfer the cooked asparagus to the ice bath to stop the cooking. Remove and drain on a paper towel-lined plate. Repeat process with second batch of asparagus.
In a small bowl, mash together the egg yolks and mustard with a fork until they form a paste. Add the vinegar and whisk to combine. While whisking, add the oil in a slow and steady stream to make an emulsified sauce. Stir in the capers, tarragon, cornichon, salt and pepper. Taste and adjust the salt and pepper to your liking. Keep in the fridge until ready to use.
To plate, crisscross a few asparagus on six individual plates. Drizzle a bit of sauce all around and top with a few edible flowers, if desired. They add color to the plate and are perfect for a springtime celebration.
I find it easiest to lay the asparagus on a board while I peel them so they don’t snap. I also trim the bottoms of the asparagus so they are all the same length as I find it presents better on the plate.