For the orange mayonnaise:
Start by preparing the mayonnaise: in the container of an immersion blender, mix the yolk, a pinch of salt, filtered orange juice and blend them while filling with oil, until you obtain a compact mixture.
Wash the asparagus and remove the ends, harder and woody, tie the asparagus with cooking twine and soak them vertically, from the side of the stalk, in a pot with a little boiling water. Like this, the tips, which are more delicate, are cooked by the steam.
When it is possible to pierce asparagus with a fork, remove them from the pot and drain them.
Then, brush a little extra virgin olive oil on the asparagus and sear them on a hot plate.
Cut the bread horizontally into two and spread the mayonnaise on the lower part. Then, add the slices of speck and complete with asparagus.
Close the other half of the sandwich and serve this tasty speck sandwich.