The egg in this recipe is important for both its texture and visual appeal. A softer boil gives the yolk a bright-yellow hue and releases an extra layer of sauciness when you bite into the sandwich.
36 asparagus spears
3 large eggs
1/4 cup grainy mustard
1 cup mayonnaise
Zest of 1 lemon
2 tsp lemon juice
6 slices rye bread
Butter, as needed
Finishing salt, such as Maldon
Prepare the asparagus by snapping off the tough parts of the stems. Cook 30 of the spears in boiling salted water until tender (about 5 minutes). Remove from pot and shock in cold water.
In the same boiling water, cook the eggs for 7 minutes. Drain and run cold water over them. Crack the shell gently, then peel under cold running water. Slice each egg in half lengthwise, then set aside.
Make the sauce by combining the mustard, mayonnaise, lemon zest and juice.
Use a vegetable peeler to shave the remaining asparagus into thin strips. Place in cold water. Butter the bread slices. Trim the ends off the asparagus so that they fit the bread, then place 5 spears on each slice. Drizzle with the mustard sauce. Place half an egg on each sandwich.
Drain the shaved asparagus and use to garnish the sandwiches. Finish with salt.